So I just updated to 4.2.1, jailbroke with greenpois0n, but after updating while syncing with my backup, it failed. I now keep trying to restore to 4.2.1 again to restore to my backup, but I cannot even restore now. The error I get is 'This device isnt eligible for the requested build', and it just gets stuck on the progress bar with 'Verifying iPhone restore with apple'. I also get Error 1600 if I try to restore once blocking Apple in my hosts file. I would really appreciate some help with this, need to get all my contacts and app data back!