Is IO locked while pressing the menu?

[]d]

Someone here is re-writing a WM using AppKit and she has a problem.
During the NSApplicationMain loop, the WM created the menu
and the first menu is popped up (not yet incorrectly) but when press on an
entry which should invoke a submenu (that suppose to open a submenu)
there is no event arrive at the ConnectionNumber(display) which has been
set to waitForDataInBackgroundAndNotify.

Suddenly after release the button pressing, some events arrived and
the WM pop up the second menu. So, my question is, why there's no
data after the mouse pressing? Testing on another WM, MapRequest
arrived at the moment the mouse is down. Writing a test code on a file
descriptor not the ConnectionNumber(display) cause the same problem,
that the notification stop working while pressing the menu.
Is this a bug or feature in GNUstep? Did we use wrong way of notification?

In case that this interrested anyone, The full source code of the WM can
be arrived at Savannah.

project site: http://savannah.gnu.org/projects/woom/
website: http://www.freesoftware.fsf.org/woom/
latest screenshot: http://freesoftware.fsf.org/download/woom/latestshot.jpg

Anyway, this is not a project annoucement.

Best regards,
]d