It was NEVER supported to play external text subtitles with mpeg. It often works, but because there are no time indexes in mpeg files, it's not easy to do the synchronization. Also, apparently there are a lot of SRT files out there with incorrect end times, i have recently become aware. I'm trying to trace the cause of this.
Ok, thanks for the reply! I'm very surprised by this - I have never seen it mentioned anywhere that mpg-files and external subs don't mix well together, not generally, nor for vlc or any other player. (And after five minutes with Google I can't find anything either. :/)
I did manage to find some mpeg1 video files that works with external subtitles in VLC, and trying really hard I can get the subs out of sync for some seconds if I stop, start and skip around a lot, but they always come back to sync very quickly. Mpeg2-files, whether it's a svcd cd, "raw" .mpg fom the cd or a vcdgear converted mpg-file, does never show any subtitles in VLC. Vsfilter for example, seem to load subtitles just fine with every kind of video, and maybe I've just been lucky with subtitles not being flawed, but nevertheless it does work.
Thanks again for your answer, and big thanks for your efforts with VLC! In large it's simply the best player there is.