2 round error

Hi,first i'm sorry for my english i'm romanian.
My pc specs:amd 3200+ 1.8 ghz
1.5g ddr2 800mhz
nvidia 7025 oc+100mhz
windows xp sp3
ultimate drivers

I play this game with 50-80 fps .
I have a problem when the game begins the second round I get an error: Crossfire has encountered a problem and needs to close . And the single button is "Close"
When i pres "Close" all my pc freeze and i need to restart them.
This error occurs only if i shoot with a gun no problem with knife and grenades!

Again i'm sorry for my english and i wait an update to resolve this problem.