DX Buffer Error

occasionally whenever i get on gw after about half hour to 1 hour everything will go laggy then stop and a small window will apear saying Dx-Buffer Error or something and then u have to click ok then in a couple sec the com will freeze then i have to reboot. but whenever my com has been on for 3-5 hours or more its fine can anyone tell me what a Dx Buffer is? and can i fix this? also what is the probelm

oops didnt mean to double post the first didnt show till after like 10min after i posted the fsecond one hehe

The first thing I'd do is open the computer up, take out the video card, blow the dust off then reseat it. See if that helps.

And get the newest DirectX Version (9c) and the newest drivers for your video card.

havent tried taking out video card.....and i know have direct 9.0c or w/e it is but i know i got it. ill try the video card thing and see if that works