What would cause a clip to play smoothly in the SOURCE monitor, but to not play smoothly in the PROGRAM monitor? Playback resolution makes no difference.
I've tried using "New Sequence From Clip" - same problem. I'm not using an external monitoring device like AJA or Blackmagic.
Boggles my mind. If you figure it out, I owe you lunch.
(Note: Sequence settings match, playback settings are the same for each monitor, software is CS5.5, computer is Mac Pro 3,1 with 10GB RAM, graphics card is an ATI Radeon HD 3870, and hard drive is fibre channel RAID.)
Have you tried reinstalling or updating video card driver?
Refresh rates are always the first thing to check - your external monitor should be set to the same refresh as the content. Playing 30p content on a 50Hz monitor will jitter and vice versa. That said I have never got external previews to playback without any stuttering at all and reading other posts around the only real solution is external hardware.
I believe the OP is referring to the right / program monitor (timeline display) of the PrP software, not an external monitor.