Hi, I have a same problem.
but It seems like only at Virtualdub.
It works at Avisynth.
i tried as follows
1,Download "Vista codec pack"
2,Install DirectVobsub and Gabest components.
3,Write Avisynth script with subtitles and so on.
4,Encode by 3gp converter.
Howevr, alert comes up when Aisynth script was dropped in 3Gp converter.
"couldn't open "C:Program FilesAviSynth 2.5pluginsavsfilter.vdf.avs"
So i have to click a button"OK" to start encoding.
therefore cannot do batch encode.
Is there anyone who knows to solve this problem?