Help needed !

My mic and push to talk button on ventrillo etc. are working fine, but when i go in game and i push my push to talk button, it doesnt do anything and noone can hear me ! but when im not in game everything is fine ! :o

what's wrong? what can i do about it? pls help !:<

edit: Problem solved ! Ty for helping... stupid i didnt think about that !:<

stupid random pic