No, I am not specifying the nHeaderHeight value.
I just tested the trimmed down sample Antonio provided, and it does behave correctly when compiled on my local machine. I thought it might just be the particular set of values I am setting, so I just copied all the xbrowse values being set in the problematic code and put them in the sample Antonio provided and it still displayed correctly. Which means it is a problem in my local code. I'll figure it out.
There may be one other issue that is telling. I grabbed 16.12 because I wanted to test the new lSeekBar feature, but I cannot get it to work at all. I just tried to enable that in Antonio's example and it isn't working in that code either. I was kind of hoping that the two problems would track together.
Thanks for having a look, for now I'll assume it is my problem.
Robb