Hey there.
I got a brand new, unlocked Samsung Galaxy about a week and a half ago. I had two immediate problems with the phone:
1. No Market
2. 3G didn't seem to be working
I fixed the lack of Market problem by upgrading to the H7 firmware. I was hoping this would also fix the 2nd problem, but it hasn't. I've also tried getting a new SIM card from AT&T, and this hasn't seemed to work either.
Obviously I may end up having to call Samsung USA at some point and request a fix, but not only might that mean I have to live without the phone for a long time, I have no idea if Samsung USA will even want to help me since I bought it 3rd-party unlocked and it isn't even officially in the states yet.
So if anyone has some ideas, that'd be appreciated.
(And yes, the "Use only 2g networks" setting is unchecked)