USPS priority mail has a tendency to not get scanned in, thus not tracked very well...But coming from Canada I don't know...(I only know about priority mail and express mail )
Express should be trackable as soon as it has entered us customs and ready to be sent out, they dont wait until it is delivered. From Canada 5 days is longer than normal though and if there is no record it means it hasnt even hit customs yet.
Date of Event Time of Event Location Description Retail Location Signatory Name
2003/12/04 19:56 Arrival in destination country
2003/12/04 02:33 Dispatched from origin country
2003/12/03 22:30 Dispatched from Canada