We need much more details to help.
- Provide us a full PhotoDVD Log.
- If it was burned with an other application, also provide us that burn log.
Not playing can be caused by lots of things, but here's a few guess.
A) You made a PAL DVD and you need NTSC
B) You used real low quality media and/or you burned it too fast
As for the subtitles, you can get see the subtitles on your PC, then is must be something on your DVD Player.
You need to turn ON the subtitles on your DVD player, and select which subtitle track to view.
Good Luck !