From the USCIS:

” USCIS Update August 17, 2007

USCIS ISSUES SERVICE CENTER AND LOCKBOX RECEIPTING UPDATE

WASHINGTON – U.S. Citizenship and Immigration Services (USCIS) announced today that it has xperienced a tremendous increase in the number of applications filed, which has resulted in a front log of ases awaiting data-entry. USCIS is making every effort to address the delay.
USCIS will prioritize data entry for specific form-types. Delay in data entry and fee receipting will not affect hange of Status or Extension of Stay eligibility, assuming all other eligibility requirements are satisfied.

USCIS would also like to assure its customers that requests for Premium Processing Service will continue to e processed within 15 days, consistent with existing policies and procedures.
The actual received date will be honored and recorded on the receipt notice. This date will appear in the Received Date” box on Form I-797, Notice of Action. The received date on Form I-797 is different from he “Notice Date,” which also appears on the Notice and identifies the date the receipt notice was actually generated.

USCIS will provide weekly updates to give our customers accurate information about current receipt times nd service level commitments. As of the date of this notice, USCIS has completed data entry and has issued receipt notices for applications and petitions received on or before the following dates:

California Service Center
Form Number:      Date Received
N-400                  7/22/2007
All Other               8/07/2007

Nebraska Service Center
Form Number:       Date Received:
I-131                     7/18/2007
I-140                     7/18/2007
I-485
Employment
Based                     7/02/2007
I-765                       7/18/2007
N-400                    7/24/2007
All Other                 8/02/2007

Texas Service Center
Form Number:         Date Received:
I-131                       6/30/2007
I-140                       8/13/2007
I-485
Employment
Based                      6/30/2007
I-765                       6/30/2007
N-400                     7/12/2007
All Other                  7/30/2007

Vermont Service Center

Form Number:           Date Received:
I-130                         7/24/2007
I-129                         8/01/2007
I-539                         8/05/2007
N-400                       7/11/2007
All Other                    8/02/2007

USCIS Lockbox

Form Number: Date Received:

I-485 Family               7/29/2007
Based

USCIS would also like to remind the public to wait at least 14 days from the dates indicated above for their receipt notice to arrive in the mail before inquiring.”

– USCIS –