I'm having the same freeze problem with my GoPro Hero 4 Black when I insert the video output board connector from the H3-3D gimbal (version 1.1--For Phantom 2 only) into the GoPro's mini-USB port and turn the GoPro on.
Just like you, I have to remove the frozen GoPro from gimbal and take out its battery to power it off. After battery reinsertion, everything's fine with the camera until I stick it back on the gimbal, insert the connector, and power the camera back on.
On the other hand, my GoPro Hero 3 Black works fine on the same H3-3D, which to me, in my case, rules out any video output board ribbon cable damage.
With a magnifying glass, I looked at and compared the insides of the mini-USB ports of the two GoPro's. There is a discernible design difference between the two. Whether that's the possible problem, who knows?
The Zenmuse gimbal, Phantom 2 (v2.0), and both GoPro's have latest firmware updates as of 11 Jan 2015.
Update (12 Jan 2015): Just to make sure it's not a problem with output board connector ribbon cable, I replaced existing ribbon cable and connector head with brand new ones. Made no difference. Hero 3 Black worked fine. Hero 4 Black went comatose once again.
For anyone interested, attached photo shows difference between Hero 4 Black and Hero 3 Black USB bays (ports)---both have 5-pin configuration but slightly different designs.