Check your audio drivers and stuff, make sure they’re current.
Moraven’s right about using Audacity instead of Fraps for audio. Fraps has a storied history of sync issues. I don’t like Fraps, personally, and haven’t used it in a long time. Have you fiddled with the audio options to see if that changes anything? I’d just as soon recommend a free alternative, e.g. MSI’s Afterburner utility, Open Broadcaster Software, FFSplit, etc.
Your mic works well otherwise, right? I mean, do you sound OK through Mumble or Audacity? If your mic’s just wonky, you can get respectable sound out of $30-50 USB dynamic and condenser mics from CAD, Samson, Audio-Technica et al. If you don’t want a stand-mount you can also get decent phone and USB lavalier mics around that price.