Help with blank navigation screen

Hi Everyone,

Last year I got a back-up camera installed in my 2007 M5. The place that installed it was Alekshop in Fremont, CA. I have noticed that when the temperature is above 82 F, the navigation screen turns blank when I place the gear in R and stays like that for at least 20 mins. The camera comes back on after 20 mins or 20 mins of continuous driving. Has anyone seen this before? If so, is it possible my specific module is getting overheated? Aleks mentioned that he has installed this camera in 500+ cars and I am the only one with this complaint. Any help you can offer would be greatly appreciated.
What is the point of having a back-up camera if it doesn't work?!