Been down this road myself due to my battery dying. I did enter the code incorrectly, after the dealer had, and it locked up the head unit. Sure enough, leaving it on for an hour and entering the code correctly did the trick. Since then my stock stereo was stolen so I couldn't tell you any more

 

WOW! What a major league waste of a theft. Steal a really crappy head unit that you can't make work anyway.

 

Thanks for everyone that's put any input to my Q... I still can't get it to work... Does the car have to actually run for a whole hour or can I just leave the ignition on?? If anyone knows, I'd appreciate a little clarity... Who knows?? Maybe some day we'll meet and I'll get the first couple round of pints!! Cheers!