Downgrading iPad 3G to 4.2.1?

[tonyunreal]

Is it possible now? Because it wasn't with the 4.3GM build, iTunes threw out 10015 error and the device restarted in DFU, kicking the device out of it with TinyUmbrella didn't work either.

The developer download page explicitly said it's impossible to downgrade from 4.3GM to 4.2.1, but since the GM IS the final build, does it mean I'm stuck with 4.3 or higher version forever?

 

[iAAPL]

Is it possible now? Because it wasn't with the 4.3GM build, iTunes threw out 10015 error and the device restarted in DFU, kicking the device out of it with TinyUmbrella didn't work either.

The developer download page explicitly said it's impossible to downgrade from 4.3GM to 4.2.1, but since the GM IS the final build, does it mean I'm stuck with 4.3 or higher version forever?

Wow! I feel amazing now. According to Apple, I accomplished the impossible. Thanks! I just did it this Sunday before I sent it out to the new owner. It took me a couple of hours to figure it out. I tried all sorts of weird combinations. I think the one that worked was clicking the Update button in iTunes (not [opt]-click), letting it try to install iOS 4.2, waiting for the fail message, attempting to kick it out of recovery with TinyUmbrella, and then manually putting it into DFU mode, and clicking the other option in TinyUmbrella (the one that's supposed to fix the 1015 error). I would just try as many different combinations as you can; it should work eventually . I don't know if you can still do it, now that 4.3 is officially out. You can try downloading 4.2 and doing the opt-click "Update" route.