If you get 1600 or 21 errors try this

We were trying to JB a friends ATV2 and kept getting errors from iTunes. After some looking around this finally did the trick…Just wanted to share to those who are down and trying to install but have these problems. 

 

http://www.iphoneheat.com/2012/01/ireb-r5-now-available-for-download/

 

Good luck…