Gmod crashes when I join another server

When I join another server after being on a server I get a “hl2.exe has encountered a problem and has closed”, is there any way of fixing this, as I have already uninstalled and reinstalled the game via steam. My graphics card is an Ati Radeon Xpress 200 but I will be getting a new one soon. My gmod plays smoothly in game but Ineed this problem fixed.