Confirmed: iTunes 7.6 needed for some successful 1.1.3 upgrades
A heads-up for those who are struggling to get iPhones updated: If you've tried upgrading your iPhone or iPod touch to 1.1.3 and are getting mysterious errors that keep you from finishing the upgrade or restore process, make sure you're already running iTunes 7.6. I'm hearing reports from various parties that pre-7.6 iTunes installations will may fail to properly upgrade iPhones and touches. After installing the newer software, the upgrades begin to work properly.
iTunes 7.6 is available in Software Update or directly from Apple.
Update: It looks like there are 1.1.3 successes on both Mac and Windows without 7.6. If you do get the update error, go ahead and upgrade but as reader responses are showing, you may not need to upgrade beforehand.
Update 2: The specific errors you may encounter are 1603 and 1604. If you get these errors, update to 7.6, and if possible reboot both iPhone and your computer.
