Just crashed my brand-new Phantom 2

[TeamYankee]

Flying with the GoPro wifi is like flying with your own personal radio jammer on board...

 

[Mako79]

There was a guy on youtube mythbusting this.
If you stay within a 50-100m, the phantom should still respond. Greater than this and the GoPro's wifi blocks/weakens the signals. In the youtube clip, the phantom did a RTH because it was not receiving any control signals.