ATI Silencer 4 fan problem....

My ati silencer 4 on my x800xt  has  a fan problem. When ever i start the computer, the fan is really, really loud (almost sounds sparatic) for about 1-2 minutes and then it goes away. I run the fan at 100% since this is a dell case, come on. Anyhow, it is not cooling the way it should be either. Right now the video card is at 41c. Usually it is lower than this with fan running at 100%. I am going to try a can of compressed air later, but for now i am stumped. Any ideas as to what is wrong?