If you use your webcam with its default control panel settings, you are likely to see some real bluriness on high motion.
To fix this, you need to go to your webcam controlpanel/property page, and disable automatic exposure and lighting, and manually set a much lower exposure (you can crank up the gain or brightness to compensate). This is equivalent to increasing the shutter speed on a camera.
You can get access to this page from within FlipSuite by going to Video/Capture options, then "Video Device Settings" tab, then selecting "Custom video device driver settings" from the Show Property Sheet combo box.
Ideally you should have some good bright lighting to compensate.
The Logitech HD C920
gives quite good results.