At work, on my test machine… if I press the PrtScn key (to take a screenshot, of course) the computer freezes completely, requiring a hard reboot. This worked fine on the same machine using Windows 2000 or WindowsXP (which aren’t exactly works of art either).
On a happier note, I’m scheduled to receive my new Mac later today.
[Update 1/22/2007] Mr. Bhadra confirms his computer freezes when pressing the PrtScn key as well. Even on a clean installation of Vista with no third party software. Maybe the key should be re-labeled Self-Destruct.