I can't update iTunes and I'm stuck now.
When I run software update, it says that there's an update about iTunes: 10.6.3 (176.9MB) And it says "iTunes: Partially downloaded (0%)" at the bottom of the software update screen.
I expect Mac to download the files when I click "Install 1 Item" button. The download progress bar shows for a millisecond and and alert is displayed:
The update could not be verified. It may have been corrupted during downloading. The update will be downloaded and checked again the next time that Software Update runs.
So I checked /Library/Updates folder and I see that there's only the dist file which is an XML file with package information but the software itself is not in there.
I tried deleting all the files under /Library/Updates folder but nothing changed...