back up camera

Hey guys,

 I have a 2005 (1/2) jetta. Put in a Pioneer Avic-D2 2-din. Also a back up camera(generic ebay). The camera has the following hookups:-VIDEO OUT(single RCA)-POWER IN(+12v and Ground)

The video out of the camera goes into my pioneer (brown RCA which is BACK UP CAMERA IN)

And the PURPLE / white (REVERSE sence IN) on the pioneer is hooked up to my reverse light.(grey/white) which is located on the back trunk lid. HERES MY PROBLEM:with ignition on the back up camera turns on fine....everytime I can see a perfect picture on the pioneer. Now when ignition is in the START position(car running) I now put it in reverse and the camera comes on. (ONLY ONCE). I put the car in park and back into reverse and it will not sence the camera again. How is this possible?!!?! The pioneer is sensing the reverse lead EVERY time. But it will only switch the camera ONCE while the car is running. Can this be a reverse wire voltage problem? COuld it be some way to program in the pioneer itself? I cannot for the life of me figure this out. THe camera works FINE with just IGN on. But when the car is started and running it will only work ONCE. after that just wont recognize. WTF!!! PLEASE HELP~~Yes I have checked power to the camera and its on with ignition and while the car is running. VIdeo RCA is fine also.

I would try to to connect the back-up camera to 12v. constant and see if that will fix the problem, if not, there should be some settings on your Pioneer for back-up camera, try to switch them around.