strange erratic behavior

[Josef Lowder]

.
My Mandriva 2006 system, which has been very stable for several months,
just started to have a very strange, erratic behavior.  I have not made 
any changes, and have not installed anything new recently.

When I move the mouse pointer over any one of the four desktop boxes 
on the status line, the system just goes crazy flashing each of the 
different desktop wallpaper images. 

When I move the mouse pointer over the start button, the start menu 
flashes on the screen and disappears, therefore I cannot do anything 
from the start menu. 

I was able to shutdown and restart by switching to a different console, 
but after rebooting, the problem remains the same. 

When I open a terminal window inside the GUI, I can enter commands 
as long as the result does not exceed the size of the window, but if 
it does, as in a directory listing with more than 20 lines then the 
display goes crazy scrolling over and over without stopping, so I have 
to kill the window to get it to stop. 

I tried changing batteries in the wireless mouse but that didn't help. 

What in the world might be causing this and how can I fix it?