I am using it fine on T-Mobile in USA for Voice, GPRS and SMS.
But it will not recognize any foreign (outside USA) networks...in any country.
If I use the same T-Mobile SIM card on another phone, like RAZR, it works in the foreign networks (so it is not the SIM card or T-Mo Service).
What's going on here ? Do I have to do something in my Q9H Registry or some thing ?