Brought a new 7960 online today in the office — and it paper weighted itself. It loaded up the Universal Application Loader, but then refused to load the new SIP firmware. I found two things that are useful, first Voip-info.org has a useful bit and second — pay very close attention the the TFTP server logs. In the end, copying the .sb2 firmware image to .sbn was the magic trick (and possibly a few extra config files they mentioned on the page above).
But I’m rather happy that these 400$ desk ornaments actually have the inteligence to un-paper weight themselves from the dreaded “Protocol Application Invalid”