Questions DVDsubedit


I have been working on editing subtitles extracted from a .ts file bij ProjectX.

I need to retime the whole subtitle stream which I know is possible in DVDsubedit. However, after remuxing everything (to DVD) the problem is when jumping to a certain chapter, the subtitle is not displayed anymore.
I tested things already, and it seems to me that when the corresponding subpicture is to close to the chapter point, it is not displayed.

1) Does anyone know how to avoid this when retiming in DVDsubedit, or what the "safe distance" is to place the subpicture from the chapter point?

2) I have no sound during editing in DVDsubedit (I mean during preview), not very handy when trying to time subpics. Is this a known issue?

Thanks in advance
Thanks, but that's unfortunately not the answer to my question.

DVDSubEdit can do this to, but I need to know what I should take into account to avoid the problem mentioned in my question.