DVDLabPro and subtitles

I am having some problems since I moved to a newer DVDLabPro version.

Until recently I had been using 1.53, always inserting different subtitles and things were fine.

Now I am trying version 2.20 and I am having problems. The program seems to do something to the subtitles that sort of moves them or adjusts them, and they end up out of sync.

I do know the subtitle sync is alright, because I test them first on my computer with the avi file, before I convert it to MPEG-2. I have been doing this for thousands of time by now, with many films and many subtitles, so I think I have learnt how to do things. I even wrote subtitles for my own videos and all that.

The problem seems to be in DVD-Lab Pro 2.20. Any suggestions on what or where should I correct what's happening?