Problem with the PCI latency , help !

Hi , I ran Sisoft Sandra Pro and it tells me that the PCI latency is high on my machine , the problem is that when I run almost any game after a while the system hangs , my motherboard is an ECS K7S5A and in the bios there's nothing to configure the PCI latency , the rest of my configuration is this :
- Athlon XP 1800+
- 256 Mb SDRAM 133 Mhz
- Geforce 4 MX 440 (Prolink-Pixelview)
- Sound Blaster Live! value
- 1 DVD Rom Creative , 1 CD-R SCSI Teac on a Tekram 315-U , 2 HD's (each on an ide cable dma 66) .

I also use the Ethernet card that came with the board and I use Windows XP Pro , if I use the system for Internet or hear music there's no problem , but when I run a game it hangs after a few minutes , please help me !