As a simple work around for this sort of issue,I use a simple screen capture package like BB Flashback to convert to mpeg - not an issue for quality because its a small pixel count to start with.
I agree with Sean. I use Camtasia. We have the IsoView software but it is so expensive and an unfair burdon to place on customers who which to view .iso files, we do our animations in other programs.
TheIsoView plugin used to be free. IsoDraw animations had a lot more potential back then, but now it's too expensive just to view.