Avisynth preview problem

[kingcrimsonster]

Selur, please fix error:
Before load this file I set on the tab "Deinterlace - QTGMC - Avisynth - order = -1 : from source headers (default)."
After load this file on the tab "Deinterlace - QTGMC - Avisynth - order = 0 : Bottom field first."
When I try to view step by step, the image goes one frame back and the next one forward. If I encode in this mode, the output file has vertical jitter.