make sure your X server uses backing-store and save-unders. To check do:
(pcrdm.cern.ch) [1002] xdpyinfo|grep options
options: backing-store YES, save-unders YES
Check your Xserver man page to see how to turn it on.
Cheers, Fons.
>
> I've got some questions concerning the visualization facilities of ROOT
> (Linux2 version with Motif2.0).
> First, if a canvas was overlapped by another window or popup, I have
> to click on it or enter a newline in the command window to have it
> repaint itself. How can I make it repainting automatically ?
>