Difference Matte Key vs Common Sense

[Neverhood]

Hello, everybody! Maybe I should RTFM, but still a helping hand LIVE is better.
Well, subj.
Premiere 2.0 PRO. CCCP (fddshow divx decoder).
I do a simple thing. Capture a frame of a still background via "File->Export Image".
Then put on a clip DMK with that image as a key. There are some characters in the clip I wish to be cut of that backround. But WTF? It just doesn't work properly. It doesn't cut some of BG where it should, it cut some of the characters where it shouldn't. I had encountered this problem in AP7.0, well, if it isn't still fixed then it's not a bug, I'm just dumb? Please help.
P.S.
There are no problems with scaling.
Strange thing: when I add a color converter before DMK and add more BLUE, effect seem to work better.

Any ideas, sensei gata?

[Scintilla]

Strange thing: when I add a color converter before DMK and add more BLUE, effect seem to work better.

/me considers going to Toshi Station to pick up some color converters.

Anyway, I tried using the Difference Matte once with Premiere Pro (1.0), and it should have worked, but it didn't. Who knows why.
You're probably just going to have to mask out the background in your image editor of choice.

[Neverhood]

Okay.. here's some more info.
I tried channel mixer before DMK and it seems there is a verystrange mapping:

Blue 0000FF in clip match Black 000000 in key image.
Blue 0000FF in clip also match Blue 0000FF in key image -_-
White match White. Entire grayscale in key image match "bluescale" in the clip.
Magneta FF00FF match Cyan 00FFFF
Cyan match Magneta.
I still have not got a match for Red, Yellow and Green.

I have an idea though. Maybe there's some bug that shifts channels concerning alpha channel? Maybe it thinks that Alpha in key image is Blue, Red is Green, Green is Red and Blue is Alpha? Or maybe it just loses Blue. Anyway it sucks.

[Gepetto]

Magneta FF00FF match Cyan 00FFFF
Cyan match Magneta.

Aren't all the magnets interfering with your work?

Anyways, the DMK has never, EVER worked for me and now I prefer not to waste any time struggling with it and just fire up The Gimp instead. So I second Scintilla's suggestion. But about the channel mixing, maybe it has something to do with a color effect you've applied to the layer you're trying to mask out?

[Neverhood]

Heck that stuff.
Made it myself.
((Invert + Opaque 50%) + Key Image) * RGB Difference (Gray) = Difference Matte Key withgout bugs and stuff.