I'm having an issue whereby the framerate of my video appears to change midway. I can't find any explanation. I don't have any rate-stretching going on.
I know it's not much of a system but I was outputting rough cuts of the example video fine until about two weeks ago.
Example video: http://www.youtube.com/watch?v=Eqrwe_OklwE
Notice how around 4:04 the motion/framerate becomes oddly slow; then at about 4:13 it appears to become 24fps again.
I've tried outputting various h.264 presets, everything from 1080p to the Youtube / Vimeo presets. I also tried removing the b&w adjustment layer; still happens.
Phenom II X4 940
ATI Radeon HD 4300
Win 7 64
4GB RAM