Here is the glitch I get.

And when I try to compress in VirtualDubMod, they say the crash details(their best guess as to cause)
An out-of-bounds memory access (access violation) occurred in module 'lagarith'...
...while decompressing video frame 20 with "Lagarith lossless codec" [biCompression=5347414c] (VideoSource.cpp:1627)...
...while running thread "Processing" (thread.cpp:120).
I really don't think it's Premiere. I switched from Avisynth 2.5.7 to 2.5.8, though I doubt thats the problem. Should I try going back to check?