Hello, htews,
After a thorough review of your post, I have come empty handed at this point to the software having any reason in particular to display this behavior. What comes to mind is the fact that perhaps your graphics card may have a somewhat out-of-date driver?
This could reflect a near perfect behavior with minimal irregularities. Do you know what card and driver you have in your computer, by chance?

Dan Faba
Autodesk Revit Technical Support