Plays in computer but not in DVD player

Hi all,

I recently created a basic DVD in Studio Pro (MacPro 10.4.11 - Running Studio Pro 4.2.1) of a full length feature doc (107 min's) .
It plays perfectly in a computer but will not play in any of the DVD players we have tested (about 5 different ones).

Does anyone have any idea what I can do to remedy this?

Thanks
Sherril

HELP......does anyone have any ideas on what I'm doing wrong???
I need to get a DVD out that will play in a DVD player.
Thanks.