Iphone 4 stuck in recovery mode

[itsmeott]

Hope some one can help me. I have an Iphone 4 that I updated to IOS5 it worked fine for a couple days then it seemed to crash. Now I am stuck in recovery mode loop, when trying to resore on itunes I get error 21. I took it to att they tried to fix it for me to no avail, at a loss as what to do. it is not jailbroken and it is also older than 1yr so no warranty.
lost with out my phone

 

[Kyotoma]

Try using TinyUmbrella to kick it out of recovery.

 

[TomH TX]

According to an Apple support document I found, but which did NOT link correctly, error 21 arises from security software. Disable the anti-virus on your computer, and try again.

"Error 20, 21, 34, 37: These errors typically occur when security software interferes with the restore and update process."