Comment 54 for bug 156550

Gentlemen - Please excuse these comments if they are out of scope here. I run
Ubuntu and have had this problem as a user since 7.10 was released. The problem
on my Dell C640 with regards to the screensaver is identical to what has been
described here, however the problem is NOT just the screensaver. When I boot
with my laptop closed and a 1440x900 LCD connected to the VGA port, the whole
screen lights up and is usable, however the menu bars only extend to the
1024x768 region (upper left corner) of the screen. ALL applications think this
is the Maximized size, although non-maximized screens can easily be dragged past
(to the right of) this region on the large screen, and they show up fine. When I
do xrandr --output LVDS --off, the LCD on the laptop shuts of, the menu bar on
the 1440x900 springs to cover the full width of the larger display, and life is
good. This exactly sounds like the overlapping rectangles issue.

However, my point is that the problem goes beyond screensavers. More can be read
about this on the ubuntu site, bug number 147363. I hope this helps.