good news, folks - sort of. after intentive search I found a link that explains how to force the 9xxxM GPU to thottle up to FULL SPEED
the downside is you have to alter and flash your video bios resulting in loosing your warranty. another downside, you have to sacrifice the throttle level. your GPU then only knows 2 performance levels: Level 0 (2D, the lowest as before) and Level 1 (previously throttle, now the highest Level). Levels 2 and above are the same as Level 1 then but since powermizer never switches to those levels - who cares.
However this doesn't solve the black VT switch issue but at least I can use the full potential of my 9xxx GPU under Linux! Damn that thing is really fast! When using desktop apps or on battery the GPU still switches to Level 0, saving battery.
Once again, you'll loose your warranty and if you are not careful you might smash your system!!!
Attached image shows Powermizer after the modification on my system.
Go here if you're willing to risk it. Scroll down to last quarter of the post.
At the end....if NVIDIA doesn't help us we have to help ourselfs