I downloaded the 3.1 from itunes but never installed when asked. I downloaded a custom 3.1 fw (Note: I did not use Pwnage tool to create it either). Anyway, I decided to just plug my iphone in and held option then clicked restore (Note:I did not put into DFU mode either) selected the custom 3.1 ipsw from my desktop, and I let it extract and completely run its course. I did not take my sim card out nor did I do anything else. When the box saying its been restored to factory settings I unplugged and let it continue to run and unlock itself until the lockscreen. Tmobile appeared 5 bars and E and cydia installed. I plugged back into itune and selected new User and sync from there my movies podcast etc. I also did a test call. So, I got no 1600 errors or any other weird things. No Pwnage tool used No DFU mode No Tmobile Sim Removed. I regularaly synced my iphone to change movies on it or add/remove apps just normal everyday sync.
Do you know if this will work on Windows? I have a Jailbroken 2G 3.1(thanks to blackra1n) but it is not unlocked. I could use redsnow...however my HOME BUTTON is non responsive and I have no way of putting the phone into DFU mode (grrr). Everything I've read on this forum thus far wants me to put it into DFU mode. Help?