Backup camera image pulsates after relay install?

[X5_Rob]

I posted this in navigation forum but now thing this is better topic for MEF...

I just installed Navtool and Boyo backup camera in my '05 X5 with factory Nav. Everything works fine with ignition on (camera kicks on when I shift into reverse) but when I start the engine and shift into reverse the camera only stays on for a second or two then switches back and forth to the nav screen... I can't seem to figure out what is different with the ignition on vs. turning the engine on... I installed relay as follows:

85= ground
86= reverse light trigger wire
87= Navtool video module trigger
87a = not used
30= switched power

Any help much appreciated...

Rob