Xdriver problems (!!!)

Hi,
I just installed Grass update 3. Everything went OK just as when I installed
the previous update, but...
I got an Xdriver problem that I didn't have the first time: if I overlap
a window on my Xdriver window, and then I move it back, the covered part
remains erased.
Since I remember that several people had problems of this kind a few months
ago, maybe the solution can be quick.

I used hpux 9 and X11R5

Thanks,
             Andrea Giacomelli
             DIIAR Politecnico di Milano
             Italy
            andreag@idra1.iar.polimi.it