Since upgrading to version 10.0.1 of iTunes, playback is bumpy Since I upgraded to version iTunes (10.0.1), playback is bumpy and full of hiccups. Typically, for video playback the video will freeze for a second or two at random times, and then skip to the current location in time, meaning that content will be skipped over. This happens every time I play videos now, and it is seriously starting to annoy me.

For mp3 playback, sporadic hiccups seem to be happening as well, but with nowhere near the frequency of videos.

The videos I play are all content purchased from the iTunes store, typically TV shows in 'standard definition'.

I have (obviously) tried to close other resource-hungry apps etc, but that does not help. iTunes is typically at 5-15% processor usage when playing video.

I use Mac OS X 10.6.4 on a 2.53 Ghz Intel Core 2 Duo MacBook Pro with 4GB RAM. Hard drive has about 10 GB of free space.

Any ideas as to what is wrong here?
This might come a little bit as an obvious question but… have you restarted your box since you installed that? A zombie process could be causing delays in other areas.

Check with /Applications/Utilities/Activity Monitor.app and sort by CPU usage to see if there’s anything “red” (zombie) or any process not behaving. 

In any case, a sane box restart (if you haven’t already) is usually a good advice. Turn the box off for a few secs and then turn it on again, the VRAM might be corrupted and a simple “restart” won’t always do the right thing. (It happens to me in the Mac Pro).

The reason for mentioning this is that your computer is more than capable to play videos. 

Do you have Perian or any other third party codecs laying around that might interfere?