Oh, about cleartype, there is this cleartype tuner: http://www.microsoft.com/typography/cleartype/tuner/step1.aspx (needs IE)

And i find that cleartype is made for black on white text, it makes light text on a dark background worse.

Edit: For me the "BGR - very rare" in step 2 looks like you describe, if that one looks better on your screen then we've found the cause.