Hey guys, I'm having a ton of trouble finding a solution to my unique situation on the interwebs, so I was hoping someone here, who has more experience with new jailbreaking procedures, would be able to give me some direction. I have a jailbroken and unlocked iPhone 3G on 3.0.0 with the 4.26.08 baseband. I want to upgrade the firmware to 4.2.1 without changing my baseband, if I can (I use a TMobile SIM). Thus far I been able to solve all the different problems associated with having such an old firmware still on my phone (I've had her for almost four years now, and never had the time to re-jailbreak - but now that there is a way to have iOS4 without a baseband update I want to.. she's getting slow) while trying to jailbreak. The issue I'm having now is with iTunes - the dread 16xx errors. I have a custom IPSW made (in Pwnagetool 4.2) and am in DFU mode, but when I go to restore from the custom image I keep getting these errors. I've tried restarting the computer, multiple different recovery modes on the iPhone, etc. The best solution I have found is iREB, but I use a mac, so that doesnt help. When I try to use the mac solutions (getting into pwned DFU mode) to the 16xx issues through redsn0w, it keeps telling me my 3g doesn't support it (probably because of 3.0.0 or something). Is there some simple solution I'm overlooking? Do I need to update to say, 3.2.1, then try to restore with the custom IPSW? Any help you could give me is greatly appreciated.