Strangely enough this problem come with RC build and not with previous beta builds. Every time my computer goes to sleep some of my drivers might not work on resume. This could be any driver like sound , graphics, DVB , TV or modem , etc. I hope that we have a fix in windows update for this issue soon 'cause it's making the whole experience terrible. I know many people have this issue so I suggest everyone with this problem to comment in this thread to show how many of us are affected. Thanks everyone.