Video effect with 11.04

[R Kimber]

I'm using 11.04 with nvidia driver 270.41.06

When I switch desktops I now find that the new desktop still has parts
of the previous desktop on it. These are normally parts of the outline of
what had been the current window on the previous desktop.  They can be
removed by forcing a redraw of the window on which they are superimposed.

Has anyone else seen this?  Is it a known issue? It didn't happen with
10.10, or with previous versions that I can remember.

Is it a fault with the video driver (I'm not sure whether 11.04 uses a
different version from 10.10), or the program that switches desktops?

- Richard.
-- 
Richard Kimber
Political Science Resources
http://www.PoliticsResources.net/