[G4] DVD Player 4.0 Won't Play

[Ron Michael]

I'm running DVD Player 4.0 with OS X 10.3.9 with a mirror door G4 
1.25mhz. When I try to play a DVD I get an onscreen message in little 
green letters that says "not permitted". The DVD files apppear to be 
okay. I exported them as MPEG-2 and burned them using Toast 7.0 and 
also using DVD Studio Pro 3. Any clues as to what might be the matter? 
I rarely use DVD Player and I've had this problem before.
Ron