Mhm.. and which codecs are used to decode your DVDs?
with the DVD playing, right-click on BSplayer, then select Options -> Filters -> Advanced, then list here all the filters in there (Video, Audio, Splitter, etc.)
Plus are you sure that subtitles are not displayed by an external app (VobSub for example)?
When DVD starts do you go to DVD menu and disable subtitles from there too?
ATM I can't test DVD playback since I have no DVDs here with me :P
If you have still problems remember that as a BSplayer PRO user you can ask for technical support from BSP team members through a direct support channel:
Contact BSplayer Support 