Multihead strangeness

[Jonathan Guthrie <jguthrie brokersys com>]

I have a Dell laptop with one of those dual video chips in it (Intel and 
ATI) and I normally run the fglrx driver for Xorg and Debian GNU/Linux 
unstable.  This computer has a VGA port for connecting an external 
monitor, and when I connect a monitor to the port, I get a nice 
dual-headed display which I can configure through the gnome tool.  
However, it will often spontaneously change the configuration, most 
often to "mirrored" or sometimes it will turn one or the other display 
off.  Sometimes, it will cycle rapidly through the options until it 
settles on one which could be any one of the four options.  This seems 
to be often related to striking keys on the keyboard or moving the mouse 
but I have observed that it has happened when the computer is untouched.

Although I have observed that that it occurs with the fglrx driver, it 
also happens with the Intel driver, so I don't think it's an Xorg driver 
thing.  Since I don't know what to make of this, I'm starting here and 
asking if anyone knows how to proceed.  I am, of course, able to answer 
whatever questions you may have.