That seems to remove them from the people list, but when you hit phone on the home screen everybody still shows up, even with HTC Facebook unchecked. Am I doing something incorrectly?
I noticed this as well and I haven't found a solution. When I open Contacts, it only shows those groups that I checked as visible. However, when I'm dialing a number or name, all groups, including Facebook, seem to be listed. Kind of annoying.