Next, the UI rendering issues can come from a lot of different sources. We use GDI+ through .NET for most all of our custom rendering. A button, at the moment, has no additional rendering functionality added by us and is coming straight from .NET. When you run into issues like this it generally points to a video driver or video card not playing nice with with Windows GDI+. I have not seen this exact issue you are having, but I have seen rendering issues related to video cards more than once as well as video settings that tie into the card to provide extended DPI resolutions, etc. Since this is happening on an isolated machine, I think I would start with a video card (if you have a spare one) and then update the video drivers to see if the problem goes away. That is the first place I would look.