1st!!! check the specifications to your set-top player to check it can play dvd-r's. See if it specifies brands (some do.)
Which program are you using to convert & burn the video? I could suggest
TMPG but other than that to see both
http://www.videohelp.com/ &
http://forum.dvd-guides.com/ & perhaps
http://www.videohelp.com/tools