Comment 7 for bug 363983

I have additional information.
Earlier in this report I posted ati.png which showed my dual screen configuration (at work).
I am currently at home. I looked at it and saw that it seems, that at bootup my system detected that it only has 1 (the built in display) connected. So from the systems point of view, there is only one display.
see the new attached image.
thunderbird still not starting when using main display.