Please help...I have succesfully jailbroken and unlocked a number of 3g and 3gs' for friends in the past using both pwnage tool and redsnow. But now I have a couple iphone 3G's that are causing a great deal of stress.

Having no luck completing jailbreaks using either redsnow or pwnage tool...seems the pwnage tool does not recognise the ipsw....redsnow crashes and does not complete the jailbrak

I have tried jailbreaking from multiple different firmware versions (downgrading firmware by using ireb and triple checking that my ipsw files are frehly downloaded, not corrupted and correctly correspond to firmware.

I even downgraded them both to firmware 3.1.3 jailbroke using and unlocked w/ ultrasnow but now the phones can't find a signal

If there a foolproof guide to successfully jailbreaking and unlocking the iphone 3g? Is there a specific firmware and software version that will work every time? Seems that there are so many versions of redsnow, pwnage, firmware and basebands and its doing my head in.

I am getting overwhelmed by the amount of information available. If someone could point out what I am missing here or simplify this somehow I would greatly appreciate it.