It seems a lot of people are having problems with iTunes 7. I have mentioned the memory leak problems with the album flipping function before ( https://goldcoaster.wordpress.com/2006/09/15/itunes-7-memory-leak-bad-news/ ) but , gee, there are a lot more… no audio on video, distorted audio, songs skipping etc. Apple are not saying a thing – hopefully it is because they are madly working on an update.
Unless it is absolutely necessary for you to upgrade to iTunes 7 right now, I would advise holding off until a bug fixed version is released – just stick with 6.0.3.
I had major problems going from v4.9 to v5, so I went back to v4.9. I skipped v5 and went to v6 but only after the first bug fix was done…once bitten, twice shy. I won’t be touching v7 for a long while.
A good article is here: http://news.yahoo.com/s/cmp/20060915/tc_cmp/193000832