Referring also to your previous posts:
Having Trouble with Subtitles Time Correction ASS Trouble
is there any special reason to use DirectVobSub for ASS/SSA subtitles?
I ask this as - in as far as I know - BS.Player has native (inbuilt) support for Sub Station Alpha subtitles (although maybe not to the fullest extent).
What happens if you
disable VobSub support? (resp. "Allow intermediate filters")?