Sorry for the delay. I forgot about this question!!! Anyways, it's hard to capture a screen shot of this activity. I will try to explain a little clearer.
Open a folder in Windows Explorer. Right-click on the background and a drop-down menu will appear. Move the cursor down to the bottom item in the menu and you will see that the highlight cannot keep up with your cursor. It will stop on one of the menu items for a little bit and then it will move down to your cursor. While it is stopped, the cursor is animated. It doesn't happen all the time. It will happen until things are cached and then it works properly. And yes, the avast icon is spinning in the system tray when the highlight is stopped. My sensitivity is set for Normal. Thanks.