Thanks again to all for your replies and the lively discussion that ensued, especially the more technical explanations.
I feel like some clarification for my case is needed.
The crushed shadows are a system wide problem on both my PC (CM) and my colleages PC (non-CM), identical setups with the HP LP2475, Win7 and nVidia Quadro FX3800. All my browsers (Firefox, Safari, IE, Chrome) show the same results and I have checked that at least Safari is applying CM. Any dark tones in any application disappear into black, be it shadows in an image in Photoshop or Windows Photo Viewer or just dark lines on a black background in AutoCAD (a problem my colleague is battling).
Since Win7 indeed finally allows for on-the-fly changes of color profiles I have just for the fun of it checked all available profiles and none of them brighten up the shadows in any way. Measuring the display quality with i1Profiler also produces a perfect result according to the software.
What really puzzles me is how even on my colleagues unmanaged PC, so basically at factory settings, the same problem occurs.