MOD - It never had any issues making calls. It was TMO network issue. Perhaps you can change the title or even remove this thread.
I loaded official FW 3.0 on my 2G iPhone using iTunes 8.2. Used redsn0w and was able to unlock the phone on Vista. Pop in my TMO SIM and it shows T-Mobile as the carrier. Tried to make calls but always fail. Pop in my ATT SIM for 3G iPhone and I can make calls. TMO SIM works in other GSM phone.
I restored back to original 3.0 FW then used redsn0w to try to unlock again. Only thing I did was choose "unlock" but not "Cydia". It does its thing - I see the running pineapple icon, it says loading bundles and a whole bunch of stuff in the progress bar and it reboots in the end. However, I'm stuck with the "connect to iTunes' screen.
The first time I tried redsn0w, I actually see BootNeuter coming up and it selected 3.9, BootNeuter ON etc. Didn't happen this time. What to do now?
I restore yet again to original 3.0 FW. iTunes finishes and says the SIM is not right and I still have T-Mobile showing as the carrier. Cannot make calls either. Phone is not activated as it shows the emergency call screen. Ok .. going to try to DFU back to original FW now.
DFU done. T-Mobile still showing as carrier but phone still not activated like before. Run redsn0W again and install Cydia and unlock. This time it finishes and BootNeuter came up. Phone is now activated, but I still cannot make or receive phone calls using my TMO SIM. It says Call Failed. AT&T SIM works fine.
It works now. I guess TMO network had some issues. TMO SIM is a pre-paid. I assumed it was working fine earlier coz' I pop it in to my spare GSM phone and it could make calls. When it was in the iPhone 2G, I can't. But I just tried again on the spare phone and it can't make either. Network fail. Kept trying on the spare phone until I could make calls, pop it in iPhone 2G and call when through fine.
Everything works now No more error 14, 23, 1600, 1601, 1603, 1604 etc. which I was getting before 3.0 using WinPwn, QuickPwn and iTunes 8.0.1, 8.2 with FW 2.0.1, 2.1, 2.2, 2.2.1 on Vista or XP.
Now on the same Vista machine, I can restore, shift-restore, DFU etc. to 3.0 with no fuss unlike before. redsn0w works better coz' all I really want is to unlock. Don't really need Cydia.