Das Keyboard not recognized?

Hello fellow Apple users!

I've just gotten the Das Keyboard Ultimate Model S for my 2009 MacBook Pro, running Snow Leopard 10.6.8. I'm using the USB port to connect the keyboard, and the first time I plugged it in, the computer asked me to hit the first key to the right side of the left Shift key, which is pretty standard whenever a new keyboard is plugged into the Mac. It recognized it as a European ISO standard, which it is.

However since then my Mac no longer recognizes it as that kind of keyboard. When I go into the "Show Keyboard Viewer", the keyboard is recognized as a US Standard layout, and an Apple keyboard as well (meaning it doesn't "see" the numpad). You can see it's a US standard keyboard, as the Enter key is horizontal, and the left Shift key is wider. (the rest of the layout is Danish, which shouldn't matter in this case)

How do I tell my Mac that this isn't the correct keyboard? I've resetted the SMC, PRAM and NVRAM. I've tried to find and delete the file "com.apple.keyboardtype.plist" in my Library -> Preferances folder, but for some reason I don't have that file. I've plugged the keyboard into my iMac, running the same OS, and here the keyboard is recognized correctly, so it's not the keyboard that's faulty.

Anybody have any suggestions/ideas?