UPDATED (twice):

Well, I went back to your file …
[deleted rest of the original comment – I wasn’t using the most up-to-date DVDStyler v.2.9.6]

Now, with this newest version (must be the one you’re using, too), there was no problem with DVD creation, subtitles and all. However, I made a test change in the video setting and lost the menu pictures (had to manually put them back in). That’s weird and suggests we’re not entirely stable here. (Be certain to do frequent “save-as” with progressive numbers to easily backtrack and try again.)

As my place-holder video is very short (2 min.), the subtitles don’t show (begins at almost 3 min.). I changed the first entry to 1 min. and it shows just fine! … but only after my player’s option was ticked to have subtitles “enabled” (and I thought technology was supposed to make things easier).

Everything seems to work fine but every button had to be checked to confirm proper navigation (a few were wrong) and proper action (a few wrong there, too). Also, the main video was set (or mysteriously reset itself) to “copy” for video and audio when it should have been “720x480” and “AC3 48K” (because we’re creating an MPEG2 video for DVD). Check your settings there, too. You should be able to generate successfully and operate the DVD normally.