Have you tried tacit's fix:
The solution is to update to iTunes 10.6.3, or in Preferences->Advanced turn off "Automatically Check for Updates".
I wonder if this is odd: I'm still running iTunes 8.2.1 with that box unchecked, but when I check it, iTunes (via Little Snitch) asks for permission to connect, and that's where it ends: Nothing about either certificates or later versions. (I've got iTunes set as "Ignored" in Software Update, but enabling it didn't change anything.)
