1015 unknown error after 4.2.1 restore

[arthurav]

I am using mac os x 10.6.
I have an iphone 3g.
I have jailbroken it using PwnageTool 4.1.3 Unlock Edition with iOS 4.2.1 and the iPad 3.2.2 IPSW. I have installed the mobile substrate package and restarted the iphone (by putting it in the autoinstall cydia folder as wireless is not working) and then put the ultrasn0w package in the autoinstall folder. After that I rebooted. The white apple on the black background showed some tens of seconds, after that ... white screen and reboot.
I have tried to restore using the same custom ipsw ... but, near the end I get ... The iPhone could not be restored. An unknown error occured (1015).
Anybody can help?

[Simon]

Make a custom firmware again this time saying no to the baseband update. Then restore to that.