Here's the other info. I am running CS5.5 on a windows 7 ultimate 64bit (service pack 1) OS. All of the recent updates have been installed on both the OS and the CS5.5. The source footage is H.264.mov from a nikon d7000 at 1080p 24fps. My video card is an Nvida GeForce GTX285. My processor is an Intel Core i7 3.33GHz with 12GB ram. I am running no third party codecs or effects. I am using the Mercury Playback engine GPU accelerator. I am using a DSLR24 frame project setting.
Here is the problem: When I bring a 1920x1080 24fps.mov file into my DSLR24 frame project, or any project setting, in my CS5.5 and open it in the source monitor it plays as if it is trying to catch up; stuttering and skipping; it plays the same on the sequence timeline until I render it. I get no error messages. When I bring the exact same file into my CS5.0, with the exact same project settings, it plays perfectly in the source monitor and on the timeline without rendering. When I bring in a 1280x720 24fps.mov or any other size file into my CS5.5 in any project configuration, it plays perfectly smoothly. Everything plays smoothly without renedering in the source monitors of my CS5.0 and CS5.5 except for a 1920x1080 24fps.mov file in CS5.5. The exact one that I need to play there.
I would have no problem cutting in my CS5.0 if it intergrated with audition; which is why I bought the CS5.5.
You, my friend, are a genius. Thank you very much for your help. It works like a champ.