iphone 3G on official 3.0 software

Has anyone been able to successfullly downgrade back to 2.2.1 I've looked through many posts here and on mac rumors and etc. I've DFU'd and tried 2.2.1, 2.0.2, with itunes 7.5, 8.1 and 8.5 Still recieving all the myriad of 1600 errors, out of ideas, currently I've gotten it to work on 3.0, but until the majority of jailbreak apps are working on 3.0 i would prefer to return to 2.2.1 has anyway successfully done this? So far I stall at the same point every time, while it's 'preparing the iphone' for the restore i error with 160x or 1620, only thing that seems to change the error code is which firmware I'm trying to restore.

Thanks in advance, I've seen a lot of posts regarding the 3.0 GM and beta's and downgrading from those, But I've not seen anything specific to downgrading the official 3.0

Also I'm on AT&T and never unlocked, just use JB for the mods/apps