Okay so yesterday I jailbroke my 3GS that was on 4.2.1 and unlocked it using redsn0w. It worked for about 30 mins and then when i installed the cydia update, it made be reboot. After this reboot, it hung on the apple logo for an hour. I couldn't get it on! I try re-jailbreaking with redsn0w. It either says "unexpected error", or freezes at "exploiting with limera1n", but doesn't work! I try using custom firmware from Pwnage Tool. It will not let me use the 4.2.1 ispw. It says "wrong firmware selected". When I try to restore with iTunes, I get error 1015. When I try to restore back to 4.1, I get error 1600. When I do pretty much any of the above, I either land on the apple logo or the connect to itunes screen. Anyone, your help is greatly appreciated.