I have 2 machines with WinXP, both running on a domain....
If I reboot the secondary, I cannot type a password in the login after hitting control-alt-delete - the mouse works fine, tab works, enter works, etc., but if I try to fill in the password - no workee..... Worse yet, dragging out the secondaries "real" keyboard - it's disconnected until I move the mouse back to my primary. Using "Logoff" and trying to log back on has the exact same issue.
2nd issue - ctrl-alt-del brings up ctrl-alt-del dialog on both machines if I was on the secondary - it immediately freezes the secondaries mouse, and the mouse reverts back to the primary screen. Until I dismiss the dialog on the primary, I cannot even get over to the secondary to click the "task manager" button.
Unfortunately, these are deal-breakers for me if there's no fix or work-around....