AE renders .mov that quicktime cannot play. VLC does play but at 1 frame/sec.

When I render using AE render queue at Best Settings and Lossless a .mov is produced that cannot be played by quicktime. VLC can play the .mov file yet the resulting sequence seems to play every 20th frame or so. Further, during rendering, when you can preview each frame being rendered, it appears to be rendering frames consistent with what VLC plays back, meaning it appears as though only every 20th frame is being rendered. The frame-rate for the comp being rendered is 29.97.

I've tried restarting my computer, restarting AE and uninstalling and re-installing AE with no change in this issue. 

Any help would be much appreciated. 

Gabriel