Phantom non existent external monitor on Mac book pro

Question

Hi all, whenever I open my mac book pro, or wake it from sleep, the screen turns blue and it auto-detects a monitor that is not attached - a generic VGA display - the image at the following URL displays when an external monitor is NOT attached:
http://ellington.tvu.ac.uk/images/displays.png
I have to click 'detect displays' between 8 and 14 (sometimes more) times to trigger another detect routine that always changes to reflect the actual state of monitors.
I have a cinema display and when connected to the MBP - on start-up or awaking from sleep, the MBP often fails to detect the connected monitor and yet displays the same display status as above a generic VGA display - click 'detect displays' 8-14 times and it detects the cinema display. Whenever the machine / display sleeps, it seems to be a lottery as to whether the true display status is retained or whether the MBP detects the phantom monitor, blackens the cinema display and requires the (getting very tedious now) detection routine to get back to what's expect. At that point, all windows have resized and shifted position. I've described the problem to several in-store genius's with no obvious answer. I did not do a clean install from Tiger, but wonder if it would've helped.
What do you reckon? Hardware failing or some strange software problem?
Thanks in advance, Ian Grant

Answer 1

Yesterday I found the same problem. I disconnected from a Dell Projector and then later that night I noticed that my computer still showed two monitors. I'm still able to connect to an external monitor and it will detect it. However, immediately after disconnect the phantom display is back.
A little annoying because I'm always having application windows open on that phantom display.
Also I noticed that when I plugged into the projector the color was off significantly, as if there was a bad connection. I tried a variety of connectors and connected my laptop to a variety of different external monitors and all of them work flawless except for the Dell Projector. (I didn't try it on another projector because I only have the one.)
My conclusion is somehow when I disconnected from the projector I hadn't fully shut down or gone to sleep or my computer was in the middle of a disconnect when I closed the lid and this interruption as my computer transitioned from 2 displays to 1 created the phantom display. Hope to see a solution to this.
Thanks