Posted 24 December 2008 - 04:09 AM
I thinks it's a hardware issue. May be related to your graphics card (check the behaviour with another one, if possible), or I think it also may relate to power supply (don't know how exactly though).
Also, similar things may happen when you practice overclocking.
So, I would
1) Check with another monitor
2) Check with anoter video card
3) If the problem persist, I would reset BIOS to defaults (use at your own risk =))
If that doesn't help - =0 don't know...
However - that's not Vista issue, hardware one most likely, i'm pretty sure.