Using PD 17 with the latest patch, I've noticed that the 'Loop Playback' functionality in the timeline does not work for me. When I'm in either clip or movie mode, and highlight a portion of the timeline and (making sure that 'Loop Playback' is selected) press play, the player goes through the selection once, and rather than looping back to the beginning, the playback marker stays at the end of the clip and stutters, like it's trying to play the last frame over and over again. Is anyone else experiencing this?