si tu vas voir la FAQ sur le site de Leadtek tu verras qu'il faut modifier un parametre dans le bios pour rendre la carte stable.
http://www.leadtek.com/faq
Voila en ce qui te concerne:
For users with VIA 4X AGP support chipset motherboards, if you can only run at AGP 2X mode, please check the followings
1.) Check your motherboard BIOS, make sure you have enable the AGP 4X support.
2.) Install the latest Drivers for your Leadtek Graphics card
3.) If the system is still running at AGP 2X mode. the following registry can force the GeForce driver to turn on 4X mode support. The 4X off registry will turn off the AGP support back to 2X mode. (after download the files, double click to install, restart to take effect)
For Win 9X/ME: 4XAGP on registry, 4XAGP off registry
For Win 2K: 4XAGP on registry, 4XAGP off registry
4.) Most VIA chipset motherboard BIOS included a function call "AGP driving value". Find this function and try setting this value to DA or EA or E7. This function is related to AGP timing. Tuning the value will help improve the stability.
** Some version of the 4 in 1 drivers come with a special not as below. Users should ignore it and go ahead and install the 4 in 1 driver. The fact is we are no longer making our own version of the VxD program.
"Special Note: (For WinFast VGA AGP users only)
WinFast AGP VGA drivers is bundled with VIA VGA VxD. For users who use WinFast AGP VGA, we suggest you to download the driver from WinFast Web site.
If you do not have access to Internet, we suggest that you install WinFast driver before install VIA AGP VxD Driver."