For some reason quicktime files are choppy and jittery during playback in Windows 8.
I have the latest Quicktime installed with no other codecs.
I tried playback in the quicktime player as well as in adobe products (premiere, after effects, etc.).
Here's a preview of what the playback looks like:
The same rotating star video plays fine on my windows XP machine.
apologies for the late reply..
I did check with the compatibility center and Quicktime is deemed compatible (certain versions at least). Some tips can be found here:
Why Is My Quicktime Video Choppy? | eHow.co.uk
Also are you running with the latest driver updates?