Dropped frames?

[blueflower999]

So I was recording my LP with Pinnacle Studio HD, and using Audacity for audio commentary, when at the end I found that way too many frames were dropped in the middle of recording, causing the audio to drift out of sync. By the end, I had whole minutes of audio that didn't have any video to go with it. Does anyone know how to fix this problem? One of my theories is that I had my internet browser open and a few other things while recording. Could closing that prevent dropped frames?