does anone knows a OVP Mod (Over Voltage Protection) for this board?

Yesterday we bench with LN2 and I can't go over 1,93 V...

second problem is that the board have very strange problems with GraphiX OC...
Every time when the system crashes because we overclock the GFX to much.
The system don't boot and give uns a beeeeeeep beep beep beep ...

after we plug out the GFX and wait some minutes
it runs...

we have this problems with all the 3 GFX Cards that we have testet
GX2
HD2900 PRO
8800 GTS 640

BIOS was 0401