In your subpictures XML file, I'd suggest specifically declaring each button, something like this:
<button name="b1" x0="0" y0="90" x1="710" y1="127"
up="b5" down="b2" />
<button name="b2" x0="0" y0="127" x1="710" y1="167"
up="b1" down="b3" />
<button name="b3" x0="0" y0="167" x1="710" y1="205"
up="b2" down="b4" />
The x0, y0, x1, y1 coordinates are, respectively, the left, top, right, and bottom sides of the box containing the button. You can find these out by opening your menu graphic in the GIMP
, or any other software that will tell you image coordinates. Most of my menus are a single column, so I just simplify things and use "0" for the left coordinate and "710" for the right side; then the y0 and y1 are just the top and bottom of each button. Make sure your image is 720x480 (for NTSC) or 720x576 (for PAL), or the coordinates will come out wrong.
I've also tried what you've done, telling it to "infer" the button locations, but didn't have much luck with it. Explicitly specifying buttons is more of a pain, but it seems to give better results, especially if your buttons are in a weird non-columnar configuration.
Also, your dvdauthor file looks OK, but I'd suggest using a separate pgc for each title, and including a "post" command with each, so it will jump back to your menu after the title finishes playing:
<post>jump vmgm menu;</post>
There are some other commands you can stick in there also, for handling other button-presses while the title is playing. Check out the dvdauthor manual for details.
All in all, I wish you luck! I have been thinking about making an open-source dvd-authoring GUI, since it's something we could sorely use. After seeing your post and others like it, I'm thinking more seriously about doing it.
p.s. - a quick, simpler solution is to try using "rows" instead of "columns" in your "autoorder" statement in the spumux file. Not sure if that will work, but it might!