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**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

 

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**FORM 10-K/A(AMENDMENT NO. 1)**

 

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**(Mark One)**
| **x** | **ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|-------|------------------------------------------------------------------------------------------|

**For the fiscal year ended: December 31, 2006**

**or**

 
| ** ̈** | **TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|-----------|----------------------------------------------------------------------------------------------|

**For Transition period                    **

** **

| **Commission File Number of issuing entity:  333-130795-12**

**Washington Mutual Mortgage Pass-Through Certificates, WMALT Series 2006-4** |
|--------------------------------------------------------------------------------------------------------------------------------------------------|

** **

**Commission File Number of depositor: 333-130795**

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**WAMU ASSET ACCEPTANCE CORP.**

**(Exact name of depositor as specified in its charter)**

 

 

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**WASHINGTON MUTUAL MORTGAGE SECURITIES CORP.**

**(Exact name of sponsor as specified in its charter)**

 

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|   |                                                                                          |
|--------|-----------------------------------------------------------------------------------------------|
|   | **Delaware**                                                                                  |
|   | **(State or other jurisdiction of Incorporation**

**or organization of the issuing entity)** |
|   |
|   | **1301 Second Avenue, WMC 3501A Seattle, Washington  98101**                             |
|   | **(Address of principal executive offices**

**of issuing entity)**                           |
|   |
|   | **(206) 500-4418**                                                                            |
|   | **(Telephone number, including area code)**                                                   |
|   |
|   | **54-2195748**                                                                                |
|   | **(I.R.S. Employer Identification No.)**                                                      |
|   |
|   | **N/A**                                                                                       |
|   | **(Former name, former address, if changed since last report)**                               |

 

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Securities registered pursuant to Section 12(b) of the Act: None

Securities Registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the SecuritiesAct.    Yes   ̈    No   x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) ofthe Act.    Yes   ̈    No   x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d)of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    x  Yes      ̈  No

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein,and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part II of the Form 10-K or any amendment to this form 10-K.     ̈  [Item 405 of Regulation S-K is not applicable.]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer.See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer   ̈    Accelerated filer    ̈    Non-accelerated filer   x

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of theAct).    Yes   ̈    No   x

Registrant has no voting or non-voting common equity outstanding held by non-affiliates.

 

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 **PART III**

The Item labeled "Item 1122 of Regulation AB: Compliance with ApplicableServicing Criteria." is hereby amended by replacing the last sentence thereofwith the following:

None of the Servicing Reports or Attestation Reports has identified anymaterial instance of noncompliance with the servicing criteria as applicable tothe respective Servicing Party, except that, with respect to:

1.  WMMSC and its compliance with Item 1122 (d)(2)(vii)(B), two		of twelve bank statement reconciliations examined were not prepared		within 30 calendar days after the bank statement cutoff date, but were		prepared within 30 calendar days after month end, which was 32 calendar		days after the bank statement cutoff date.

2.  American Security Insurance Company and Standard Guaranty		Insurance Company (together, "Assurant") and their compliance with Item		1122(d)(4)(xii), during the reporting period covered by this 10-K Annual		Report, Assurant did not have sufficient policies and procedures in		place to capture the information necessary to determine its compliance		with Item 1122(d)(4)(xii). As stated in a letter dated January 30, 2008		and attached hereto as an exhibit to this 10-K/A, Assurant has implemented policies		and procedures to capture the information required to comply with this		provision.

 

 

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**PART IV**

**Item 15. Exhibits, Financial Statement Schedules.**

 

|   | (a)(1) | Not Applicable. |
|--------|--------|-----------------|

 

|   | (a)(2) | Not Applicable. |
|--------|--------|-----------------|

 

|   | (a)(3) | Not Applicable. |
|--------|--------|-----------------|

 

|   | (b) | Exhibits |
|--------|-----|----------|

 

 

| **Exhibit No.** | **  Exhibit Description**                                                                                                                                                                                                                     |
|-----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|            |                                                                                                                                                                                                                                               |
| 4.1*            | Pooling and Servicing Agreement (incorporated herein by reference from Exhibit 4.1 to the Form 8-K filed by the issuing entity on May 12, 2006).                                                                                                   |
| 4.2*            | Mortgage Loan Purchase Agreement (incorporated herein by reference from Exhibit 4.7 to the Form S-3 filed by WaMu Asset Acceptance Corp. on December 12, 2005 with respect to Registration Statement No.333-130795).                               |
| 4.3*            | Amended and Restated Administrative Agent Agreement (incorporated herein by reference from Exhibit 4.9 to the Form 8-K filed by WaMu Asset Acceptance Corp. on March 6, 2006 with respect to RegistrationStatement No. 333-130795).                |
| 31*             | Certification of Thomas G. Lehmann pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                      |
| 31.2**          | Restated Certification of Thomas G. Lehmann pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                                                                                                                             |
| 33.1*           | Report on Assessment of Compliance with Servicing Criteria for WaMu Asset Acceptance Corp.                                                                                                                                                         |
| 33.2*           | Report on Assessment of Compliance with Servicing Criteria for Washington Mutual Bank.                                                                                                                                                             |
| 33.3*           | Report on Assessment of Compliance with Servicing Criteria by Washington Mutual Mortgage Securities Corp.                                                                                                                                          |
| 33.4*           | Report on Assessment of Compliance with Servicing Criteria for Washington Mutual Bank fsb.                                                                                                                                                         |
| 33.5*           | Report on Assessment of Compliance with Servicing Criteria for American Security Insurance Company and Standard Guaranty Insurance Company.                                                                                                        |
| 33.6*           | Report on Assessment of Compliance with Servicing Criteria for LaSalle Bank National Association.                                                                                                                                                  |
| 33.7***         | Restated Report on Assessment of Compliance with Servicing Criteria forAmerican Security Insurance Company, Standard Guaranty Insurance Company and TrackSure Insurance Agency, Inc.                                                               |
| 33.8***         | Letter dated January 30, 2008 regarding Restated Assessment for the Reporting Period of January 1, 2006 through December 31, 2006 for American Security Insurance Company, Standard GuarantyInsurance Company and TrackSure Insurance Agency, Inc. |
| 34.1*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria for WaMu Asset Acceptance Corp.                                                                                                                |
| 34.2*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Bank.                                                                                                                     |
| 34.3*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Mortgage Securities Corp.                                                                                                 |
| 34.4*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Bank fsb.                                                                                                                 |
| 34.5*           | Attestation Report of PriceWaterhouseCoopers on Assessment of Compliance with Servicing Criteria for American Security Insurance Company and Standard Guaranty Insurance Company.                                                                  |
| 34.6*           | Attestation Report of Ernst & Young LLP on Assessment of Compliance with Servicing Criteria for LaSalle Bank National Association.                                                                                                             |
| 34.7****        | Restated Attestation Report of PriceWaterhouseCooperson Assessment of Compliance with Servicing Criteria for American SecurityInsurance Company, Standard Guaranty Insurance Company and TrackSure Insurance Agency, Inc.                          |
| 35.1*           | Servicer Compliance Statement of Washington Mutual Bank.                                                                                                                                                                                           |
| 35.2*           | Servicer Compliance Statement of Washington Mutual Mortgage Securities Corp.                                                                                                                                                                       |
| 99.1*           | Excerpt from Section 2 of the Term Sheet (incorporated herein by reference from Exhibit 99.1 to the Form 8-K filed by the issuing entity on May 12, 2006).                                                                                         |
|                 |                                                                                                                                                                                                                                                    |  |

** **

 _________________________________

| *    |   | Previously Filed                                                 |
|------|--------|------------------------------------------------------------------|
| **   |   | Exhibit 31.2 replaces previously filedExhibit No. 31             |
| ***  |   | Exhibits 33.7 and 33.8 replace previously filed Exhibit No. 33.5 |
| **** |   | Exhibit 34.7 replaces previously filed Exhibit 34.5              |

 

 

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**SIGNATURES**

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registranthas duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

 

 Date: May 9, 2008

 

|   |  **WAMUASSET ACCEPTANCE CORP.** |
|--------|--------------------------------------|
|   |                                 |   |
|   |                                 |   |
|   |                                 | By: /s/ David Beck |
|   |                                 | Name: David Beck |
|   |                                 | Title: President and Senior Officer in Charge of Securitization of the Depositor |

 

 

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**EXHIBIT INDEX**

 

 

 

 

| **Exhibit No.** | **  Exhibit Description**                                                                                                                                                                                                                     |
|-----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|            |                                                                                                                                                                                                                                               |
| 4.1*            | Pooling and Servicing Agreement (incorporated herein by reference from Exhibit 4.1 to the Form 8-K filed by the issuing entity on May 12, 2006).                                                                                                   |
| 4.2*            | Mortgage Loan Purchase Agreement (incorporated herein by reference from Exhibit 4.7 to the Form S-3 filed by WaMu Asset Acceptance Corp. on December 12, 2005 with respect to Registration Statement No.333-130795).                               |
| 4.3*            | Amended and Restated Administrative Agent Agreement (incorporated herein by reference from Exhibit 4.9 to the Form 8-K filed by WaMu Asset Acceptance Corp. on March 6, 2006 with respect to RegistrationStatement No. 333-130795).                |
| 31*             | Certification of Thomas G. Lehmann pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                                                                                                                                      |
| 31.2**          | Restated Certification of Thomas G. Lehmann pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.                                                                                                                                             |
| 33.1*           | Report on Assessment of Compliance with Servicing Criteria for WaMu Asset Acceptance Corp.                                                                                                                                                         |
| 33.2*           | Report on Assessment of Compliance with Servicing Criteria for Washington Mutual Bank.                                                                                                                                                             |
| 33.3*           | Report on Assessment of Compliance with Servicing Criteria by Washington Mutual Mortgage Securities Corp.                                                                                                                                          |
| 33.4*           | Report on Assessment of Compliance with Servicing Criteria for Washington Mutual Bank fsb.                                                                                                                                                         |
| 33.5*           | Report on Assessment of Compliance with Servicing Criteria for American Security Insurance Company and Standard Guaranty Insurance Company.                                                                                                        |
| 33.6*           | Report on Assessment of Compliance with Servicing Criteria for LaSalle Bank National Association.                                                                                                                                                  |
| 33.7***         | Restated Report on Assessment of Compliance with Servicing Criteria forAmerican Security Insurance Company, Standard Guaranty Insurance Company and TrackSure Insurance Agency, Inc.                                                               |
| 33.8***         | Letter dated January 30, 2008 regarding Restated Assessment for the Reporting Period of January 1, 2006 through December 31, 2006 for American Security Insurance Company, Standard GuarantyInsurance Company and TrackSure Insurance Agency, Inc. |
| 34.1*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria for WaMu Asset Acceptance Corp.                                                                                                                |
| 34.2*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Bank.                                                                                                                     |
| 34.3*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Mortgage Securities Corp.                                                                                                 |
| 34.4*           | Attestation Report of Deloitte & Touche LLP on Assessment of Compliance with Servicing Criteria by Washington Mutual Bank fsb.                                                                                                                 |
| 34.5*           | Attestation Report of PriceWaterhouseCoopers on Assessment of Compliance with Servicing Criteria for American Security Insurance Company and Standard Guaranty Insurance Company.                                                                  |
| 34.6*           | Attestation Report of Ernst & Young LLP on Assessment of Compliance with Servicing Criteria for LaSalle Bank National Association.                                                                                                             |
| 34.7****        | Restated Attestation Report of PriceWaterhouseCooperson Assessment of Compliance with Servicing Criteria for American SecurityInsurance Company, Standard Guaranty Insurance Company and TrackSure Insurance Agency, Inc.                          |
| 35.1*           | Servicer Compliance Statement of Washington Mutual Bank.                                                                                                                                                                                           |
| 35.2*           | Servicer Compliance Statement of Washington Mutual Mortgage Securities Corp.                                                                                                                                                                       |
| 99.1*           | Excerpt from Section 2 of the Term Sheet (incorporated herein by reference from Exhibit 99.1 to the Form 8-K filed by the issuing entity on May 12, 2006).                                                                                         |
|                 |                                                                                                                                                                                                                                                    |  |

** **

 _________________________________

| *    |   | Previously Filed                                                 |
|------|--------|------------------------------------------------------------------|
| **   |   | Exhibit 31.2 replaces previously filedExhibit No. 31             |
| ***  |   | Exhibits 33.7 and 33.8 replace previously filed Exhibit No. 33.5 |
| **** |   | Exhibit 34.7 replaces previously filed Exhibit 34.5              |