How to fix it?

Also, there is one more problem, that the resizing syntax' are automatically appended at the starting of the script and then it gives an error of Invalid Arguments. The script at default is like this:

Lanczos4Resize(640,272) # Lanczos4 (Sharp)DGDecode_mpeg2source("C:\Files\LBC.d2v", cpu=4, info=3)
ColorMatrix(hints=true, threads=0)
#deinterlace
crop( 12, 58, -12, -56)

Lanczos4Resize(640,272) # Lanczos4 (Sharp)
fft3dfilter(sigma=2.0,plane=4, bt=4, bw=32, bh=20, ow=16, oh=10, sharpen=1.2)
degrainmedian(limity=4, limituv=6, mode=2)
tweak(hue=1.0, sat=1.1, bright=1.13, cont=0.9)

Undot() # Minimal Noise
On doing some changes from the interface, after removing the syntax manually, again adds the syntax at the starting and at times the changes to the script are lost too. Is it a bug?

Thanks!

PS: Solution posted on Doom9 as well <forum.doom9.org/showthread.php?t=144938>