Game plays fine, then freezes

Hello, I was playing frequently, up until the mutant patch was added. Since then, I have been unable to play.

Upon entering a game, things run fine, the game runs smooth and fast. But at a certain point, approximately five minutes into any game, the screen locks up, I can hear some audio in the background, usually followed by a "Mutants Win", and then nothing.

After this, I am forced to restart my computer to exit crossfire.

Is this a common problem? Is it because I use a router?