OK - over to you

[cuneus]

XP SP2 + patches
MP10 + Divx
BFG 6800GT std

When I play a video (sometimes) the screen goes haywire magnifying about 4 times and shows lines (like the telly). PC is still working but mouse clicks do not register where they should, keystrokes to restart.

What I have tried:

Made Divx player default
Uninstalled MBM5 (only recent addition)
Tried latest nvidia drivers (and other versions) currently on WHQL v71.89
No problems with temps
Can play games e.g. BFV for hours
Removed and reinstalled MP10

None of these has helped

Any ideas ?

TIA