I'm getting the same error. I got the notification of update once. But, then , i could not update at that point. I'm trying to check again and it gives me "Unable to check for update" again and again.Updating iOS sucks.... be it apps , be at OS update... every 15-30 days, i get about 80-100 app updates and when i tried to "update all", it always reports "not enough storage available" error. I deleted my backups, apps and ensured 5.6 GB is available. Still it complains with same error. I had to update the apps one by one and it takes about 8-16 hrs to complete all updates... I'm just sick of this update thing.i tried to sell it and unable to find any buyers...I just can't rid of this ipad2!!!