This is a complicated problem, there are so many things that can cause this.
First thing I recommend is burning the DVD at less than maximum speed. If your media and drive are capable of 8x burn rate, try burning at 4x instead. Just because it can burn at 8x doesn't mean it's a good burn. PC DVD drives usually have much better read sensitivity than home DVD players. At 8x burn rate, the drive's laser is being whipped hard and drive makers may be using marginal power levels, ones good enough for playback on the same drive but not home DVD players.
I use a 16X Memorex and never had a problem, so far. But I've used a Lite-On LDW451 in the past that over drove the Laser diode and it slowly degraded to the point I couldn't even burn at 1x.
If that doesn't fix the problem, then it may be a Nero DVD burn setting problem. If you can get Ulead to compile your project as an image into a folder on your harddrive, then use Nero Express to burn that as a DVD-video project. For some reason, the Nero Express burns are more reliable than the straight Nero DVD-Video burns, I think because Express uses better default settings.
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