If you use AVG Anti-Virus on Windows (or on a Windows VM), you might want to disable it until they send out a patch for their latest update. According to a rapidly filling Apple Support thread, the latest update flags iTunes.dll and iTunesRegistry.dll as "Trojan horse Small.BOG". There isn’t a listing for "Trojan horse Small.BOG" on AVG’s website so the flag is somewhat strange.
Another work around is to add "C:\Program Files (x86)\ipod" as an exception under Resident Shield>Manage Exceptions>Add Path.
Oh, right, you use Mac and haven’t had anti-virus software in years? Via Slashdot