What i have...
8GB iPhone 3G
My phone was unlocked and jailbroken. Something happened and it was restored and will not jailbreak again. I have tried pwnage and redsn0w. I can't get it to unlock and jailbreak again. any help would be greatly appreciated. Right now it's asking for the original sim card from at&t and i don't have it as i am in germany. I have been using my vodafone sim in it until recent events.
What version of PwnageTool or redsn0w? You should be using PwnageTool 3.1.5 or redsn0w 0.9.4 only to jailbreak iOS 3.1.3. You cannot use current versions of these tools, they will not recognize the firmware revision. Also, since you upgraded to 06.15.00, make sure you remove the baseband update from any iOS .IPSW you are attempting to restore or else the restore will fail. This was documented in the dev-team's warnings before upgrading to 06.15.00 -- if you didn't read them then, you should definitely read them now. They impact how you can and cannot restore your phone now that it is permanently on the 06.15.00 baseband.