The rounded scrollbar clashes visually with the rest of the Nodoka-Squared variant, and goes against user expectations of "squared" themes in general.
Thanks for the report. This somehow slipped my mind. Should be fixed now in git :)
Much better!
One oddity remains, but it seems to affect the rounded variants also. The mouseover highlight for the scrollbar in Firefox 3 beta 3 is noticeably fainter than it is in fully native GTK apps like Nautilus.