[verified:EXPLORER] does not deactivate an already activated application in traywnd when clicking in empty desktop area

ros r74930
This issue happens with our explorer in ros AND when using only our explorer.exe (without rshell) on Windows XP: Therefore it's 100% sure that this is no problem in WIN32SS or shell-classes. Our explorer is broken here - I guess bug is in traywnd.cpp.
Repro:
1.) Have an arbitrary application opened in windowed mode and activated. Make sure the window is active in its Window caption as well as in traywnd (it's pane must be in pressed state).
2.) Now click on the desktop.

Expected behavior (what MS explorer would do):
The Windows caption bar gets grey (inactive) and the traywnd pane gets into unpressed state. No pane is pressed then.

Observed behavior:
The Windows caption bar gets grey (inactive) but the traywnd pane stays in pressed state.
Nothing is logged then.

I tested with shell windows, rapps_new, third party apps. All fail the same way for me. On ros and under Windows XP.