Rear DVD problem on 2007 esv

I have a 2007 escalade ESV and was wondering if anyone could help me with my rear dvd trouble.  When I turn off my escalade with the dvd showing on all 3 screens when i return to start it again it will only start playing on the front screen and the rear 2 screens both glow a black color. If I press stop and play again then it shows up on the rear 2 screens. does anyone know if the rear 2 screens should start playing automatically when I start it or do I always have to be mess around with the touch screens to make it start playing.  thanks for you help.

see attached sounds normal...cut paste link...for some reason the whole link only works when you cut and paste entire link, including balck font

http://arrc.epnet.com/autoasp/data.asp?sid=9217237&uid=s5524901.main.autorefctr&type=pdf&ff=078000\076859.pdf&btitle=2007 CADILLAC ESCALADE&yr=2007