Large progs/files only output as audio

Ever since I've updated to the newest version of X, I can't output any long-format or high res programs correctly. No matter what the setting, it crunches and crunches, and produces an Mp4 or MOV that's only got audio. I've deleted X, the preferences, and re-installed. I've deleted compressor, the preferences, and reinstalled. The problem persists. All of my programs are locked inside X and I can't export anything broadcast-ready.

If I select a smaller portion of the timeline and use exact-same output settings, I get a complete file with audio and video.

Any ideas?