I cant understand whats going on so will need some help here :)

I gonna encode a avi file with subtitle to mpg with TMPGEngc. First time it works without any problems. But the sub was wrong, so I used another subtitle to encode it once again. But now the probs came up. VirtualDub crashed, all time I tried it. I just cant understand why?? I made exactly same as 1 time.

I used Subtitler plugins with virtualdub 1.4.7, frameserved it after all settings, then opened the vdr file in TMPGenc 2.50 and so on.
It started to encode but QLAWAYS after a while virtualdub crashed. Had tried it many times now but cant make it work like first time I enocded it..
Anyone can tell me or what more do u need to know?