I've been working on this problem for a couple of days and have a work around, but it is not pretty! I've tried everything I could think of including uninstalling using Revo Uninstaller to remove all the crud and a fresh install. I also downgraded and then upgraded again. The downgrade fixed the problem but it came back after upgrading again. I am also running WinXP as others above.
For now the only fix is to downgrade and stick with the old version. Unfortunately, the downgrade is not simple because the library file in ...My Documents\My Music\iTunes\iTunes Library.itl cannot downgrade. If you have an old backup you can use this. Otherwise you must delete it and allow iTunes to rebuild it from scratch. This means reimporting the entire music collection.
I have gon back to v 10.2.2 which I know was stable from 6 months ago...
- Uninstall iTunes
- Remove ...My Documents\My Music\iTunes\iTunes Library.itl
- Download iTunesSetup1022.exe (or another old version) from oldapps.com and install
- Run iTunes
- When the popup "A new version of iTunes is available...", check "Do not ask me again" and select "Don't Download"
- Re-import your music collection
Enjoy!