Is safe to SBF?
Downgrade to the 2.4.330 Firmware
IF YOUR FIRMWARE VERSION IS 4.5.629 - DO NOT ATTEMPT THIS PROCEDURE: 4.5.629 included a change to the BootLoader which locks it to the .629 Firmware. If you flash D2G Firmware to a version prior to .629 you will essentially "Brick" your handset, because the BootLoader won't accept anything other than .629, and the .SBF file for 4.5.629 has not yet been leaked from Motorola, leaving you with a handset with a BootLoader and nothing more. There are multiple message board threads of users who have Bricked their D2G this way. Simply search "4.5.629 SBF" and you will find them. (5 April 2012)