I did, and when I went to restore the backup of my comms and calender it rebooted. At first I thought it was part of the restore as it does a reboot but it did it immediately and when it loaded up I saw it hadn't restored anything.

I then tried the restore again and it worked, but then it seems to be rebooting more and more as I use it. I think the reason it took so long to reboot after I did the reflash (about 18 hours) was because I hardly used the phone as it didn't have any of my contacts, email accounts, IM accounts or calender setup.

I will probably reflash again this weekend just to be sure but I'm pretty convinced it's a hardware issue and I'll be sending it home next week.