Hi ah ok that could be the problem yes
Well try this. a good person who helped me out rnf wrote:
Now, for the instability, do you mean that the X interface freezes periodically? A co-worker had this problem on a PC with a VIA chipset and a GeForce2. He had to tweak some BIOS settings:
* AGP Driving Value: you might try DA here but be careful not to go too high (I've read that anything under E2 is safe but some chipset require EA), it might damage your hardware
* disable AGP Fast Writes
* force AGP 2x
* disable PCI Delay Transaction
And that made my Xserver much much more stable.