No, card isn't overheated. No artefacts or freeze or slow during first 5-7 minutes of game. (At low videomemory setting) On big island i can play 5-7 minutes, at small island at least 30 minutes. And then i see 2-3 second freeze and black screen. Iа ш press esc i can see mouse pointer, i can click on places where may be a button and they are pressed.
Ati support say that it is only game problem, because problem there is only one game.