Ok, I did some further investigation and found that the problem doesn't occur
with tkMessageBox.
The reason can apparently be found in msgbox.tcl:
# Message boxes should be transient with respect to their parent so that
# they always stay on top of the parent window. But some window manag
Martin, Jeff, Russell,
thanks for the replies,
> Could you share a small snippet of code that exhibits this behavior? I
> use XFCE4 by default but can test with at least GNOME (I think I still
> have KDE on an older machine somewhere...) I also have a couple of
> version of Tk installed so we
