I changed to these settings and saw no improvement in the Black Death track - actually lost one fps in average but that is out of the statistic margin as I only ran it once...
However it feels smoother in actual gameplay but I'm pretty sure it's placebo or some pseudo Hawthorne effect
Never underestimate that one for us glass half full people
As a side note - is there really any support in DirectX for 32-bit bit depth? Windows classic 32-bit color is really 24-bit with 8-bit alpha (just as the original setting) - even though there has been talk of increasing it - but I guess the human eye is really lost after 24 any way?
EDIT: Even if the setting is really not valid (though there is a DirectX D3DFMT_D32 depth buffer available in Dx9 it's deprecated in Dx10 for something else - does it really work on todays hardware?) - it's really interesting that some people here see massive improvements (as some side effect I guess by driver/dx going to some default setting instead?). The devs analyzing that could lead to good stuff!