I got a 3G, and I've used 3.0 and now 3.0.1 with no issues at all. Mine is legally unlocked (bought from Australia).
What you can try is, go to Settings > General > Reset and select (Reset Network Settings) and see if that does anything.
If that didn't work, If it were me I would just restore to 3.0.1 by downloading that firmware and select restore on itunes while holding shift and select the 3.0.1 ipsw. But ofcourse I don't know if your phone is legally unlocked or not and I also don't know if you know how to jailbreak\unlock if you need to so I can't advise on that.
I got a 3G, and I've used 3.0 and now 3.0.1 with no issues at all. Mine is legally unlocked (bought from Australia).
What you can try is, go to Settings > General > Reset and select (Reset Network Settings) and see if that does anything.
If that didn't work, If it were me I would just restore to 3.0.1 by downloading that firmware and select restore on itunes while holding shift and select the 3.0.1 ipsw. But ofcourse I don't know if your phone is legally unlocked or not and I also don't know if you know how to jailbreak\unlock if you need to so I can't advise on that.
Try that and let us know how it goes.