I was able to (finally) edit a multicam project in Vegas 11 Pro at 23.976 fps. When I rendered to mp4 at the same framerate, it looks almost like the footage was undersampled to 18-20 fps. I have no idea what's causing this. I tried rendering to mpeg and don't have this problem, everything renders fine. It's AVCHD video, 1440x1080. Any ideas?

Edit: Turns out the option to have source adjust frame rate was doing it. Which it shouldn't, but I disabled it and my rendered footage is playing fine. Another Sony upgrade!