black screen when enabling dual screen on dell latitude notebook

[MrGuga]

When using the key combo FN+F9 to change between Internal/External/Both monitors, (for example, after docking the notebook on the dock station), it cycles through the following modes:
- Both on, clone mode (lower resolution because of different monitor sizes)
- Internal on, External Off
- Internal off, External On
- Both on dual screen mode, BUT BLACK SCREEN ON INTERNAL SIDE, i can go with my mouse on the black side, but can't carry any application to it.
- Again same mode (at least i can't see any difference from the previous mode)

This used to happen with the vanilla xorg that came with karmic, i then started to upgrade xorg from ppa and it solved. Now it is broken again.

Current workarounds:
- Restart X Session (Logoff and Login)
- Manually set dual screen mode on system > preferences > video

I don't remember what was the version of the working xorg package, is there any aptitude log or something like that?

Also, i dont know if this is the same bug or if i should file another one, but whenever i close OR open the lid when having external monitor plugged in, instead of disabling/enabling internal monitor it works as if i had pressed the FN+F9 key, cycling through modes. This way i always end up in having the wrong mode (usually i get a dual screen with lid closed, or single screen with lid open). Works fine without external monitor plugged. Workaround is to manually set video through system preferences or to cycle through modes with the FN+F9 combo (altough now i end up with the black screen problem if i use the combo keys)

my current xorg version is 1:7.4+3ubuntu10
Karmic Koala 64bits
Dell Latitude E5500 (Intel GMA 4500MHD)
I use a Dell Dockstation