I was about 300m away about 30 m up in a heavily treed area. I got a brief weak video strength warning so I spun around and headed back. All of a sudden, the app image went to black and white and froze. The controller seemed happy however and I was able to initiate a return to home which worked fine. I decided to see if I could recover the video link so I unplugged my phone and tried to switch the view onto the controller. Nothing worked. I landed, rebooted the EVO and everything was fine again. I am glad it did not lose control link. Any body have this happen? Is there a recovery method?