Losing image display with Topaz Studio 1.11.5

Just upgraded to Topaz 1.11.5 and if I use my iMac scroll pad to zoom into the image, it completely disappears. Also, when I attempt to open another image, it is never displayed. They show up in the browser thumbnails and the filters load properly, but the image does not display or vanishes once I attempt to zoom in or out. The previous version never had this problem. If the image appears at all, it usually reappears when I switch to a different image in the browser and switch back. But it can also eventually reach such a state where it displays nothing.