cgminer randomly resetting Windows 7

[batman, not crabman]

Hey guys,

I'm running cgminer 3.0.1 (also had this issue with 2.11) and every few hours I find my computer stuck half way through booting at the Windows 7 screen.  I think it's locking up when it tries to load the AMD drivers.
So what I think is happening is cgminer crashers and somehow causes Windows to restart, then it locks up on reboot.  If I turn it off and back on it boots but not before asking if I want to run startup repair.

So:

Has anyone had this issue with cgminer and have a fix? or
Does anyone have a fix for it locking during boot (cgminer runs automatically when Windows boots so I'm not worried about 2 lost minutes every few hours)? and
How do I get startup repair to stop coming up after a failed boot? It defaults and is a pain in the ass when there is no monitor plugged in as I can't tell if it's booting Windows or launching startup repair.

I'm running 4 x 6950s on risers. An ASUS, XFX, Sapphire and MSI.  All are at default clocks. MB is a GB 990 FXA UD3.

Thanks

[Schleicher]

There is more than one possible explanation for the reboot:
1. it gets too hot
2. the graphics driver has a bug
3. the power supply is failing

[batman, not crabman]

There is more than one possible explanation for the reboot:
1. it gets too hot
2. the graphics driver has a bug
3. the power supply is failing

1. possible, although it has been much hotter and been fine (heading into winter here in Aus and had a spell of 30+ C days a few weeks back.  It gets 35+ in my house when that happens.
2. also possible, I'm using the latest 13.1 AMD drivers though and it was stable for long-ish periods (3-4 days) previously
3. I hope not, it's a brand new 1200W FSP.  Any way to tell?