The FC40 Phantom runs a 5.8ghz Transmitter and receiver to help improve the distance from the very first version of the phantom... DJI was smart enough to make all their cameras like the FC40 camera 2.8ghz and on the phantom 2 Vision camera 2.4ghz as well.
The firmware update is suppose to change by default into D-Bus mode, but doesn't for lots of people. Make sure you set your mode to D-Bus for now on.