I have installed my Mk IV a few days ago only to find out that the drivers are not compatible with Windows XP x64, so now it pains me greatly to have to install yet another M$ OS on this PC to get the Catweasle to work.
Let me know how yours works for you. Are you using AmigaForever, AIAB or just WinUAE? I am using AF2005 and like it alot. I'll keep using my "Real Amigas" as long as they continue to boot up, but it is nice to know that when all the old hardware finally dies the Amiga experience will still be available on modern hardware. The programmers that have worked long hard years at perfecting WinUAE have my highest regard and appreciation.