Fraps

Dayum....i'm having some problems with fraps. I have the exact same set-up each time but some days it works,more days it doesnt and its getting really annoying now since I want to save some replays before I go on my holidays next week (i'll be in france with no internet so i'll do some editing,Windows Movie Maker ftw!). Am I doing something wrong and ret@rded yet again,since I'm an idiot with computers,or what the hell's going on. Cheers.