I have the Apex 500 no-letter, looks like the 500WM but had the -1MM bios. Was getting what looked like a frame drop problem, either in capture or IVTC, or so I thought.

Finally got some time to do some analysis, problem NOT in original cap file OR in converted MPG, on DVD looks like 2 to 5 frames suddenly accelerate, effect does not occur in slow or stop motion, but does happen consistently at same spot. Does NOT happen on VCD. Effect is almost subliminal, usually get a couple per movie.

Had close-up of train wheels starting up, you know how you see them slip a bit when they start to move? This looked just like that, except the source video showed a smooth, gradual progression, no slip.

Upgraded to Apex 660 Bios from CD, easy upgrade, this has eliminated the problem. What an easy fix!!!