Multicam angle viewer frozen during edit
I'm just starting to edit a three-camera interview with FCPX's otherwise elegent multi-cam edit feature. However as I play the multi-clip in the timeline, the cuts are being effected properly via keystroke, as they should, however the clips in the angle viewer are frozen in place forcing me to guess at where to make the cuts as the timeline runs. I can scrub through the multiclip in the media browser and it moves the three angles then. But they stand still when I try to edit.
I've restarted FCP. I've restarted the computer. I've zapped the PRAM. I've repaired permissions multiple times. I've trashed permissions. I even changed the clip to proxy media. Nothing's working. What up here?
iMac, OS X Mountain Lion (10.8.5)