I have a 2006 vintage MacBook Pro (Intel Core 2 Duo) and have been using Boot Camp since it was in beta. I had been running XP SP2 on it with Tiger quite happily.
I've recently wiped and reinstalled everything to upgrade to Leopard. After installing Leopard, I fired up the Boot camp assistant and used it to install the Windows 7 RC. That worked really nicely, but my HFS+ driver didn't work under Windows 7 yet so I decided to install Vista instead.
I didn't repartition the drive, just launched the Vista installation disk from BIOS and told it to overwrite the existing Windows 7 install. It installed fine and I installed the Boot Camp drivers, still all fine.
Now, however, every time I boot into Windows and login it hard reboots itself as the desktop is appearing. After this it works fine again. Until the next power off.
Has anyone had any similar problems? Or can offer suggestions on how to solve this?