Subpictures do not fit in letterbox 16:9 mode

THX, that helped.

Now everything works right on my standalone-player, I resized vertically to 434 pixels and added black to get back to 576 pixels. But now I have the problem that Software-Players (PowerDVD, WinDVD) resize the subpicture and the buttons don't fit again. Is the only solution for full compatibility to make appropriate 4:3 menus?

hmm, ill have to check that one out, which maybe a little hard without a dvd burner or a standalone to play DVDonCD. Enf...

I played around a little bit with those options in the Track Properties Tab and now its working everywhere !!! The strange thing is, that I had to set the options the other way round. For Wide I chose the resized picture and for Letterbox the unresized, this whole thing is a (little) bit strange, but now I'm glad that it works.