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                                                                    EXHIBIT 10.4

                      AMENDED AND RESTATED PROMISSORY NOTE
                      ------------------------------------
$64,574,049

                                                             Englewood, Colorado
                                                              September 29, 2000

     FOR VALUE RECEIVED, the undersigned, Liberty IB, Inc. ("Maker"), promises
to pay to the order of Liberty Media Corporation ("Payee"), at 9197 South Peoria
Street, Englewood, Colorado 80112, or at such other place as Payee may from time
to time designate by written notice to Maker, in lawful money of the United
States of America, the sum of SIXTY-FOUR MILLION FIVE HUNDRED SEVENTY-FOUR
THOUSAND FORTY NINE DOLLARS (US $64,574,049) plus interest from the date of this
Note on the unpaid balance. All principal and interest is to be paid without
setoff or counterclaim as set forth below. Maker further agrees as follows:

     Section 1. Interest Rate.


          (a) Until an Event of Default (as hereinafter defined) has occurred or
maturity (whether by acceleration or otherwise), this Amended and Restated
Promissory Note (the "Note") will bear interest at a per annum rate of 9% from
the date hereof, compounded annually.

          (b) Interest shall be computed on the basis of a year of 365/366 days
for the actual number of days elapsed.

          (c) After an Event of Default has occurred or from and after maturity
(whether by acceleration or otherwise, and before as well as after judgment),
all unpaid principal and accrued interest shall bear interest until it is paid
at 2% in excess of the interest rate otherwise applicable to the unpaid balance
under this Note.

          (d) All agreements between Maker and Payee are expressly limited so
that in no contingency or event whatsoever shall the interest paid or agreed to
be paid to Payee for the use, forbearance, or detention of the indebtedness
evidenced by this Note exceed the maximum rate permissible under applicable law
(the "Maximum Rate"). If under any circumstance Payee should ever receive an
amount which would represent interest in excess of the Maximum Rate, such amount
as would be excessive interest shall be applied to the reduction of the
principal amount owing under this Note and not to the payment of interest.

     Section 2. Payments.


          (a) Principal and interest shall be due and payable as follows:

               On or before one business day following receipt by Maker of a
cash distribution in respect of the interest in Liberty IB2, LLC, a Delaware
limited liability company which has been pledged as security for this Note
pursuant to the Security Agreement (as defined below), a payment equal to the
amount of such distribution shall be due and payable.


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To the extent any amounts remain unpaid, all outstanding amounts owing under
this Note, including unpaid interest and principal, shall be due and payable on
September 28, 2008. All payments shall be applied first to accrued interest and
then to principal.

          (b) Maker shall have the right to prepay this Note in full or in part
and without premium or penalty three business days after giving notice to Payee
of Maker's intention to prepay this Note. All such prepayments shall be applied
first to accrued interest and then to principal.

     Section 3. Modification; Security. This Note is a modification, and is
issued in substitution (in part) for, the Promissory Note dated October 21, 1999
originally issued by LDIG Financing LLC, as maker, payable to the Payee. This
Note is secured by and is entitled to the benefits of the Security Agreement
(the "Security Agreement") made as of September 29, 2000 in favor of the Payee
by Maker.

     Section 4. Default. It shall be an event of default ("Event of Default"),
and the entire unpaid principal of this Note, together with accrued interest,
shall become immediately due and payable, at the election of Payee, upon the
occurrence of any of the following events:

     (i)  any failure on the part of Maker to make any payment when due, whether
          by acceleration or otherwise;

     (ii) any failure on the part of Maker to keep or perform any of the terms
          or provisions (other than payment) of this Note or the Security
          Agreement;

     (iii) Maker commences (or takes any action for the purpose of commencing)
          any proceeding under any bankruptcy, reorganization, arrangement,
          readjustment of debt, moratorium or similar law or statute;

     (iv) a proceeding shall be commenced against Maker under any bankruptcy,
          reorganization, arrangement, readjustment of debt, moratorium or
          similar law or statute, and relief is ordered against it, or the
          proceeding is controverted but is not dismissed within 60 days after
          commencement thereof;

     (v)  Maker consents to or suffers the appointment of a receiver, trustee,
          or custodian to any substantial part of its assets that is not vacated
          within 30 days; or

     (vi) upon the occurrence and during the continuation of an "Event of
          Default" under and as defined in the Security Agreement.

     Section 5. Waivers.


          (a) Maker waives demand, presentment, protest, notice of protest,
notice of dishonor, and all other notices or demands of any kind or nature with
respect to this Note.


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          (b) Maker agrees that a waiver of rights under this Note shall not be
deemed to be made by Payee unless such waiver shall be in writing, duly signed
by Payee, and each such waiver, if any, shall apply only with respect to the
specific instance involved and shall in no way impair the rights of Payee or the
obligations of Maker in any other respect at any other time.

          (c) Maker agrees that in the event Payee demands or accepts partial
payment of this Note, such demand or acceptance shall not be deemed to
constitute a waiver of any right to demand the entire unpaid balance of this
Note at any time in accordance with the terms of this Note.

     Section 6. Collection Costs. Maker will upon demand pay to Payee the amount
of any and all reasonable costs and expenses including, without limitation, the
reasonable fees and disbursements of its counsel (whether or not suit is
instituted) and of any experts and agents, which Payee may incur in connection
with the enforcement of this Note.

     Section 7. Assignment of Note. The Maker will not be permitted to assign or
transfer this Note or any of its obligations under this Note in any manner
whatsoever except with the prior written consent of the payee.

     Section 8. Miscellaneous.


          (a) This Note may be modified only by prior written agreement signed
by the party against whom enforcement of any waiver, change, or discharge is
sought. This Note may not be modified by an oral agreement, even if supported by
new consideration.

          (b) This Note shall be governed by, and construed in accordance with,
the laws of the State of Colorado, without giving effect to such state's
principles of conflict of laws.

          (c) Subject to Section 7, the covenants, terms, and conditions
contained in this Note apply to and bind the successors and assigns of the
parties.

          (d) This Note constitutes a final written expression of all the terms
of the agreement between the parties regarding the subject matter hereof, is a
complete and exclusive statement of those terms, and supersedes all prior and
contemporaneous agreements, understandings, and representations between the
parties. If any provision or any word, term, clause, or other part of any
provision of this Note shall be invalid for any reason, the same shall be
ineffective, but the remainder of this Note shall not be affected and shall
remain in full force and effect.

          (e) All notices, consents, or other communications provided for in
this Note or otherwise required by law shall be in writing and may be given to
or made upon the respective parties at the following mailing addresses:


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                  Payee:            Liberty Media Corporation
                                    9197 South Peoria Street
                                    Englewood, Colorado 80112
                                    Attention: General Counsel

                  Maker:            Liberty IB, Inc.
                                    9197 South Peoria Street
                                    Englewood, Colorado 80112
                                    Attention: General Counsel

Such addresses may be changed by notice given as provided in this subsection.
Notices shall be effective upon the date of receipt; provided, however, that a
notice (other than a notice of a changed address) sent by certified or
registered U.S. mail, with postage prepaid, shall be presumed received no later
than three business days following the date of sending.

     IN WITNESS WHEREOF, Maker has executed this Note effective as of the date
first set forth above.

                                         LIBERTY IB, INC.


                                         By:
                                                  ------------------------------
                                         Name:    Mark D. Rozells
                                         Its:     Executive Vice President




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