What screenmode do you play your games in?
To get good scrolling your bgcPC needs to be using a screenmode of 640x512 (@50.18 hz or 100.36 hz) or 320x256 (@50.18 hz or 100.36 hz)
Is that how you have been playing them?
If not then you can create the correct screenmodes using PowerStrip.
Please don't play your recorded games in 800x600. We want perfection! Thanks.