I don't have an answer and have found this problem too when recording a live video stream of a sporting event - I thought it was just the bad connection from Italy to Australia.
I guess if others are experiencing that it might have something to do with the frame rate the software is recoding at. When shooting video you get jerky movements when you start shooting above 1/50th shutter speed.
I've just done a google search and found this helpful info on a competitor's website http://www.techsmith.com/tutorial-camtasia-recording-performance-prior.html
it also talks about another codec to record in - DivX - I haven't played around with this
So you need to select an appropriate frame rate for what you are trying to capture and lossless or lossy as per above
hope that helps - I'm no expert though