No HDR in CoD2, to my knowledge.
beedubaya: I don't know why your DX9-class card should not be able to use the DX9 renderer in CoD2 (which it obviously isn't, it's the only explanantion as to why it looks so crummy). Are you sure you haven't got any IQ-degrading options enabled in Catalyst? I ask again: Does DX9 RTHDRIBL look like it should?...