TG-UV2 has a hidden option "lock/unlock" function. I discovered this feature when I tried to enter the frequency 438.000MHz and...there was no such possibility. I didn't know why, but my TG-UV2 was locked and could only operate up to 432.000MHz.
This is solution:
1. turn OFF radio
2. press and hold MON+PTT (both buttons on the side)
3. turn ON and wait about 3 sec for an extra "beep"
4. now you can release PTT+MON
Now the radio is locked, and if you repeat this procedure once more then it will be unlocked (or vice versa).
If your TG-UV2 is not locked, then you can ignore this feature. This tip is presented in case your radio somehow ends up locked (often with "DIS" on the display when you try to transmit on a frequency that should be permitted) and you need to unlock it.
More details and discussion here: http://tg-uv2.blogspot.com/2010/08/frequency-coverage.html#comments