Haven't Received Your I-797 Receipt Notice for your TN Petition Submitted at the VSC? USCIS Reports that Receipt Notice Issuance Continues to be delayed.
"Due to an unusually large volume of receipts at the Service Centers, it is taking longer than expected to enter cases into the system. Depending on the type of case and service requested, it may take approximately 14 days to generate and mail receipt notices. Once the receipt notice has been generated, it may take an additional 2 to 3 days for customers to receive their receipt notices in the mail. Per existing policies and procedures, requests for Premium Processing Service will continue to be processed within 15 days. USCIS wishes to assure all customers that the original 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 is different from the "Notice Date", which also appears on Form I-797. The Notice Date is the date the receipt notice was actually generated. USCIS has taken appropriate measures to address this situation."
-From the USCIS website (last visited July 11, 2006).