What was your total bitrate?
If you used LPCM audio (1.536Mb/S for stereo 48Ks/S) and a high bit rate on the video compression, your total bitrate may be too high for all DVD players. 9.8 Mb/S is the absolute limit for DVD of any sort. Older DVD players' drives spin the disk at only one fixed speed and can't handle high bit rates until the head is farther out from the hub, if at all.
While LPCM may be universal on all vintages of players, MP1/2 is nearly as well accepted and it will save you 1.1Mb/S on your total bitrate.
AC3 is only accepted on the newer (in the last 4 years) players and the bit rate is about half MP1/2
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70