Here it is, Jelly. Turns out Kwag's script is fine (the actual source is also stretched)
#================================================= =====#
# -= AviSynth script by MovieStacker v2.0.0 (beta3) =- #
#================================================= =====#
LoadPlugin("C:\Program Files\MovieStacker\Filters\MPEG2Dec.dll")
LoadPlugin("C:\Program Files\MovieStacker\Filters\GripFit_preview.dll")
LoadPlugin("C:\Program Files\MovieStacker\Filters\UnFilter.dll")
LoadPlugin("C:\Program Files\MovieStacker\Filters\LegalClip.dll")
LoadPlugin("C:\Program Files\MovieStacker\Filters\Sampler.dll")
AviSource("C:\Source\whatever.avi")
ConverttoYUY2
LegalClip()
GripCrop(528, 480, overscan=2, source_anamorphic=false)
GripSize(resizer="BilinearResize")
UnFilter(50, 50)
TemporalSmoother(1, 2)
MergeChroma(blur(1.5

)
MergeLuma(blur(0.2))
GripBorders()
LegalClip()
--------------------------------
Still doesn't explain the ToK problem, though...