i just recently purchased an unlocked 9300 tmobile branded 3g blackberry and would like to use it on at&t. i know the phone functions will work perfectly but what steps are necessary for me to get all my blackberry features working such as push email, blackberry messenger, also i heard the 3G isnt compatible cross network since allegedly the 2 networks use differing 3G frequencies. will reloading the blackberry 9300 with the latest os6 firmware/ or att branded firmware fix any of these problems?