Yep, Lakri, I've found that as well. I was really looking forward to it as I often used Quark XPress as a journalist on the Mac OS.
Newspaper production is almost invariably Mac-based and I'd always been hoping to get an affordable PC-friendly version for home use.
I went through all the registration hoops - it took ages - and when it was finally installed found the same problem as you.
Don't think I could afford upgrading to XPress 7.
Isn't Vista just great!