What you may have experienced with regard to delayed I-129 receipt notices has been confirmed. It seems that USCIS is busy with a higher than usual number of I-129 filings at present, and thus, is issuing I-797 receipt notices a little later than usual. This news comes from the American Immigration Lawyers Association (AILA).
The high volume of I-129 filings is almost certainly due to increased H-1B petition filings by cap-subject employers who are trying to make sure that their petitions receive numbers under the FY 2013 H-1B cap. As of May 18th, 42,000 H-1B petitions had been counted toward the regular H-1B cap and 16,000 had been counted toward the advanced degree cap.
For now, I-129 receipts are likely to be issued within 30-60 days of filing an I-129 petition. AILA’s notice states that , “Customers who do not receive notification of receipt within 60 days of their delivery confirmation date should contact the appropriate Service Center for further information.”
The situation is anticipated to be temporary. Things will most likely return to normal after the H-1B filing rush has passed.