UPDATE: I had a good look at my network card, and it sais this:
So it's based on the RAlink RT2561 chipset.
This is what the product's site sais:
Comprehensive Operating System Support: Windows98/SE/ME, Windows 2000, Windows XP,
Windows CE, Linux, Mac OSX
Thoug it doesn't work on
Mandrakelinux 10.1 Community edition.
I DO want to contact RAlink, i just don't know how. They have like 5 different E-Mail adresses. I can't call because i'm from the Netherlands.