Azimutz, I'm looking at your dumps and DSDT, I think there is something we can do about that.
One Problem I see is the following :
In my DSDT, the GMA related code (which shouldn't exist) uses some variables it gets from bios in the GNVS Operation REgion. I can't find the same thing in your DSDT. These variables are used to know which port is activated with what kind of device. But, since GMA is integrated, there little chances for this change, so I think we can hardcode it without too much problem (after all, it is hardcoded for my real graphics card, has been replaced, no pb).
What I need from you is to know what kind of outputs are driven by the GMA : how many ports, VGA, DVI (w/ or w/o Dual-Link) , HDMI...
I have the GMA _ADR value all right, what I need is the same for each connectors. That is all.
@CEOS, I looked again. My asumption was right, vertical blanking is vertical blanking. But it has been recalculated automatically, it seems (cvt calculation is really not necessary for the second table.) Those in the first table aren't, I'm wondering what is the relation between the two...
EDIT: did some testing to reproduce the bug, but didn't succeed. All I got is plain black band, not exactly what guys have. CEOS, when you're in the boot menu and type something (like -v or -s) do you see the text appearing above the band ?