My problems began with a bigger project, but for the sake of finding the problem, i simplified it alot:

I have one menu with a button that links to a five second movie. Thats it.
I've done this in both DVDLab and DVD Architect with the same results.

1)I create the DVD folders and open up the IFO with PowerDVD and WinDVD. They work fine.
2)Now I burn the folders onto a DVD and try again. PowerDVD and my Panasonic DVD player dont work, WinDVD does. (PowerDVD freezes, and my DVD player says it cant play this kind of disc)
3)If I try to open the IFO on the DVD from PowerDVD rather than play the whole DVD, still doesn't work.
4)After a while I got bored of trashing DVD's so I created images with ImgTool instead of burning actual DVD's. Then I used VirtualDaemon to mount them, the results the same.

This problem seems so fundamental, its extremely annoying. Id just like to figure it out and get on to some real things.

Any ideas where this could be coming from?