First thing is do not depend on Auto Update to keep your computer current. The only things downloaded and installed with Auto Update are those items deemed as critical for security by Microsoft.
So first thing you need to do is go here and follow all the steps:
http://www.mtu.com/upgrades/hoster/xp-changes.htm
How much memory on your video card?
Video cards without enough memory (128 - 256mb) will cause and have all kinds of problems with the version 4 releases.
How big is your hard drive and how much free space is left?
What I am looking for here is whether your hard drive is getting filled up which will cause problems and generally is over looked when searching for the problem. It would not be a bad idea to delete all the temporary files for the computer and Internet Explorer every couple months and defragmenting the drives to help make things run better.
I think the sync problem is because of the audio glitch you are getting in each song. So if we can figure out the cause of that then the sync problem should go away.