I just registered to reply to you asking if you ever worked it out as I was having the same problem. I'd tried downloading teh Desktop SW again and checked updates for the phone (none).
But in between work and waiting for the verification emails to come in I carried on as usual.
Then I got requests to update some apps and, as usual, this required a reboot of the Torch. When I next connected it via USB to the PC, it backed up and synched as normal.
So I don't know WHY, but it's working again. Good luck!
