scrolling is sluggish if overview shown in complementary view

Open a CDS/Protein split view, and an overview for one of the views. Now try (on OSX) trackpad to scroll in the other view (ie CDS view for a protein overview). Scrolling is jerky/sluggish or doesn't even work at all. Seems like
a repaint thread starvation issue, since clicking into the other view (with the overview) and scrolling the trackpad doesn't work until a few seconds after the jerky scrolling has stopped, and then catches up.