I think you are on to something. I just checked the ipsw and it's:
iPhone1,1_3.1.2_7D11_Restore.ipsw
A buddy gave me the ipsw I have, it appears to be for the 2G. DOH!
This link helped:
http://www.quickpwn.com/2009/10/jailbreak-and-unlock-iphone-3-1-2.html
Once I get home, I'll take another crack at this mutha. Thank you for the tip!
Well, I don't know what to say without being mean (other than details are everything when altering your phone, pay attention)
OK, since you have a 3G your firmware MUST begin with "1,2"
In the future, get your official Apple IPSW's from a safe place, not your buddy...
Firmware download links