If you have iTunes 7.5 and sync your Gmail POP settings to your iPhone or iPod touch with software version 1.1.3, updating to iTunes 7.6 may result in not being able to check mail on your Gmail account because the POP account settings were not changed to IMAP. You may see the following error message:
"Cannot Get Mail
The connection to the server "imap.gmail.com" failed"
To prevent this, update to the latest version of iTunes such as iTunes 7.6 or later, prior to updating your iPhone or iPod touch to software version 1.1.3 or higher and then sync your Gmail account settings to the iPhone.
Use these steps if you have already updated your iPhone or iPod touch to software version 1.1.3 and are experiencing issues with your Gmail account after updating from iTunes 7.5 to iTunes 7.6: