Need help with easy overclocking

[Yesod]

I have an ABIT BP6 motherboard with 2 celeron 433.
I can overclock both to 488 without any problems... but when I run a game that uses my Geforce DDR... hang !

I didn't overclock the Geforce... only the CPUs... and I left 2/3 for the AGPClock thing in the bios...

I even tried to 'underclock' the Geforce but it's not better...
Any ideas ?

[engjohn]

try giving the CPU's a little more voltage...

[Yesod]

I tried to push it to 2.2 v but no change :(

It must be related to the video card because it freeze as soon as I'm in a 3D game...