[WIN32SS] Right mouse button down on already activated taskwnd pane does not deacticate the title-bar

ros r74973 since the recent fixes our explorer behaves much better on ros and windows XP.

Here is a bug that is very likely not caused by our explorer, but broken deeper in ros:
-activate some window, e.g: cmd (you can use any arbitrary app here)
-make sure its title bar is activated and the taskwnd pane is in pressed state
-now click-n-hold with the right mouse button on the cmd-pane in taskbar

Expected result:
The title-bar gets deactivated as long as you hold the button. Title-bar gets activated again as soon as you release the mouse button and the context menu of the pane opens.

Our explorer behaves perfectly in Windows XP SP3 in this scenario.
Our explorer behaves perfectly in Windows 2K3 SP2 in this scenario.

Observed result when doing the same on ros:
The title-bar stays erroneously activated the whole time while I click-n-hold the right-mouse-button. We log nothing then. When I release the mouse button later everything is ok in the end, the title-bar is active and the context menu pops up.
But during the time holding the right button we expect the title-bar to be gray