Amazing, I get the same result as you Bill, but only when using the
Microsoft ICM colour engine for the conversion instead of
Adobe (ACE). Which one dis you use?
Funily, I had completely rejected to use Microsoft's ICM because I experienced strong hue shifts in a single conversion to Lab and back. If you remember I showed about this
here, and have checked it again with the girl's picture and it happens again: when going to Lab and back just once with the Microsoft ICM engine, clearly highlights become more blue, while the rest of the histogram seems well preserved.
I am using PS CS2. No idea what's going on here, perhaps others can say.
BR
PS: BTW download a new version of Histogrammar 1.2, some minor things have been improved.