also with color mapping hsv-exponental, gamma2.2, colors bleach out. Which would be the best way for using a 2,2-gamma AND avoiding color desaturation? (Right now i push color saturation via post after rendering wich doesn´t feel like the correct way)
try linear mapping, or if using that you get bright burnt-out areas switch to reinhard and drop the burn value until it looks right.
You’ve probably already done this but just in case make sure ‘Affect colour selectors & material editor’ boxes are checked in the Max Gamma setup. Without these on what looks like say a bright red in the mat editor/colour swatch will in fact render a pale red.
well, thanks a lot - i fear that was the problem, didn´t correct the shaders 
Do you know about Auto Gamma?
http://www.chaosgroup.com/forums/vbulletin/showthread.php?t=42988