Do you have an example project that illustrates the problem you are running into? If so, please send the source code to email@example.com
and I'll take a look.
I checked the code and created a test project, and the StopHotTracking method does get called on a MouseMove, but this method and the InvalidateRect call does not get called if the mouse doesn't move. Therefore, I'm not quite sure what you mean by "painted endlessly". Also, the rectangle that is invalidated is the rectangle that contains the tabs. I do not see the parent painting endlessly as you describe.