i have a c2d 17inch 2ghz. the fans just came on really loud, even though all i had open were several safari tabs, msn and itunes. it stayed this loud for about thirty seconds then very gradually faded out...this has never happened before! i was a little worried, so restarted the machine but this didn't seem to have any effect, they just continued to fade out until evenutally stopping. should this be a cause for concern? i shut it down and turned it back on and now it seems alright. i'm just a little confused is all!