Certain popup windows in gnome-character-map are closed prematurely when running
xfwm4, but not other window managers.
Steps to Reproduce:
Run gnome-character-map and right-click on a character in the grid. When running
metacity or no window manager, the popup window persists while the right mouse
button is held down. When running xfwm4, the popup window flashes up briefly
(with title ?? in the taskbar) and disappears almost immediately.
The popup window should not be closed immediately.
$ xfwm4 --version
This is xfwm4 version 4.2.2 for Xfce 4.2.2
built with GTK+-2.6.7, linked with GTK+-2.6.8.
Fixed in SVN, both branches. The problem is not really a bug in xfce, but rather
an assumption from gucharmap about how focus is managed by the window manager.
gucharmap creates the popup of type UTILITY, assuming the WM will not focus it.
If it does, that that generates a focus out event in the main gucharmap window
which then unmaps the popup (causing the problem you reported).