ok, had my first issue but easily resolved by a genius in the Los Gatos, CA Apple store. I could not synch my iPhone after installing Leopard. I kept getting an error message that a plug-in was interfering. The genius found the plug-in and removed it. (I tried reinstalling iTunes several times with no success before going to the store). Now so far all is fine! (by the way I have no idea where the plug-in came from).