Just tried on a computer with 10.2.8 running iTunes 4.0.1 then 4.1. I also tried installing over a previous version of X-Tunes or as a brand new one. The only problem I found was with the global install (i.e. for all users) where X-Tunes would not work correctly after installation, so I removed this option from the installer.
If you already installed X-Tunes and you are experiencing troubles, trash it, redownload and re-install, but for the local user only.
If you still experience troubles, please send detailed explanations along with config info to info@pol-online.net, so I can have a look at it, thanks.