If you have your radio unlock, try updating to 2.32.00WU (the stock radio is 2.23.00). I had freezing issues all the time with the 2.23.00 radio and after I updated the radio, I have no freezing issues and battery life is excellent (and I have data on all the time).
Go to
http://forum.ppcgeeks.com/showthread.php?t=106571 to find out about the radio.