Having trouble with a straight 29.97 Apple Pro Res HQ 50GB movie export from FCP 7 playing with an unpredictable studder in Quicktime 7.6.6 Pro. The same file plays smoothly in Quicktime X. It plays smoothly on the Apple TV and DVD disc but the stutter shows up again when compressed to h264 via Compressor and uploaded for private streaming online. It is most noticeable during some of the graphics (created in After Effects) during the pans. It is not the same every time and varies. It plays smoothly within Final Cut Pro 7 and there are no drop frame notices. I have a Mac Pro Tower, Version 5,1 Quad Core Xeon - 3.2 GHz with 6Gb Memory and an ATI Radeon HD 5770 graphics card. I have several multi TB 7200 rpm internal drives installed with plenty of space available on the different drives. I find this problem to be very unusual and I'm wondering if anyone else has run into it/resolved it? I've never had a situation before where Quicktime X played a file better than Quicktime 7 Pro.