Derek
How did you burn the DVD exactly. Did you burn it to a folder and then go from there? OR did you burn it directly?
If you burned it to a folder and then burned from the folder, you have essentially burned a data DVD. From my experience these folders are sometimes (more often than not now) recognized on regular DVD players, because a lot of them are designed to read data DVDs. MACs however, will read the DVD as a bunch of .vob files, not as a cohesive DVD.
This may not be your problem, but this is certainly one that I ran into at one point and this is what what explained to me as to why the DVDs didn't work in a MAC computer, so thought this just may be of some help.