Some users are unable to install iTunes 9.2, receiving a message indicating that an error has occurred and installation could not continue.
Fix
Delete iTunesX.pkg. In many cases, this issue can be resolved by navigating to /Library/Receipts/ then deleting the file iTunesX.pkg (note that this is the Library folder at the root level of your hard drive). After deleting this file, retry installation of iTunes 9.2.