iTunes is prompting for backup password

[Limitless]

When I having my iphone 4 need to upgrade to IOS 5. So I just back up with through the iTunes 10.5 and download and installed ios 5. I am now going through all the step-up process and it is at collect or restore all from the iTunes backup step. I attach to iTunes and iTunes is prompting me for a password to "unlock your iPhone backup file." No I did not encrypt the iPhone backup, nor is it or was it checked in iTunes. I have try my iTunes password, my 4 digit unlock code for the iPhone, and a number of other passwords. When I did the backup an hour ago I was not asked for a password. I am at a loss as to what it is.

[robot.txt]

I've receive the same difficulty. I don't recall each setting up a password on my backups. Plus, while I look back in time machine, the backup’s folder was not present earlier this morning.Now there is a backup file, so it should be the backup it did prior to wiping the handset during the upgrade.

[Bala Murugan S]

I have the accurate same issue! Tried with each likely password I could think of (Apple account one, computer password, etc) and not any of them work. I have a selection at genius bar at local Apple Store, but I have doubts they can even help with this issue

[DawnSet]

Same difficulty here, updated to ios5, never encrypted my backups, and tried all passwords, screen lock pass code, none work. Very annoying as basically historical data msgs contacts are now gone. Is there some standard password iTunes set to the backups??

[TamaraAce]

Well I finished up leaving to Apple Store and looking for help out from the geniuses... no help out there. I finally that I wish to make sure that to try using a password cracker and it didn’t get long for it to find the password to the backup file. Wish for to guess what it was? Try "1234". Yeah... that's what worked on mine. Even with the password, looks like my backup file was corrupted somehow. None of the music, videos or apps was restored.