Exhibit 24.1

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears
below constitutes and appoints Ralph Quinsey and Stephanie Welty, jointly and severally, his or her attorneys-in-fact, each with the power of substitution, for him or her in any and all capacities, to sign any amendments to this Annual Report on
Form 10-K and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, hereby ratifying and confirming all that each of said attorneys-in-fact, or his or her substitute or
substitutes, may do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, this Registration
Statement has been signed by the following persons in the capacities and on the dates indicated.



|                                              |  |                                                                                                                                |  |               
|--------------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------ |  | --------------
|Signature                                     |  | Title                                                                                                                          |  | Date          
|                                              |  |                                                                                                                               
|/s/ RALPH G. QUINSEY Ralph G. Quinsey         |  | President and Chief Executive Officer (Principal Executive Officer)                                                            |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ STEPHANIE J. WELTY Stephanie J. Welty     |  | Vice President, Finance and Administration, Chief Financial Officer and Secretary (Principal Financial and Accounting Officer) |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ STEVEN J. SHARP Steven J. Sharp           |  | Chairman of the Board                                                                                                          |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ PAUL A. GARY Paul A. Gary                 |  | Director                                                                                                                       |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ CHARLES SCOTT GIBSON Charles Scott Gibson |  | Director                                                                                                                       |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ NICOLAS KAUSER Nicolas Kauser             |  | Director                                                                                                                       |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ WALDEN C. RHINES Walden C. Rhines         |  | Director                                                                                                                       |  | March 15, 2007
|                                              |  |                                                                                                                               
|/s/ WILLIS C. YOUNG Willis C. Young           |  | Director                                                                                                                       |  | March 15, 2007