Well, I just redownloaded dgavcdecnv108.zip and suddenly, magically everything is fine.
(i've almost gone nuts at this point..)
So I just looked up the two different "dgavcdecnv108.zip" files.
You updated the nvcuvid.dll right? I had downloaded dgavcdecnv108.zip before you reuploaded it with the updated nvcuvid.dll.
Seemingly the bug was in the old nvcuvid.dll:
DGAVCIndexNV 1.0.8 to the
left with
new nvcuvid.dll, to the
right with
old nvcuvid.dll
dunno what to say finally.. hm..
problem solved, thanks anyway.