Is it just 10.2 users who are having problems? I have 10.3 and iTunes 4.5 and it works fine, but it seems 10.2 has problems. Why this should be I don't know - it doesn't make much sense since the features I added do not depend on 10.3 specific APIs as far as I know. If 10.2 users are willing to contact me by eMail I can build diagnostic versions that may help pinpoint the problem. Unfortunately debugging visualisers is difficult as iTunes won't run with a debugger present, so indirect methods (like log output) is required. Some idea of which configs do and don't work is also handy - if any 10.2 users have this working I'd like to hear from you as well. Fixing the problem should be easy, but understanding it might take a while.