Popup Menus Sticking (not disappearing)

Hi, I am running version 4.77. I have an issue going on that no one seems to have ever had. In my nodes, when I right click on them to see the actual data, the data comes up. Now, when I right click the menu windows (ex: Sort, Hilite, Copy, etc., etc.), they pop up but don’t disappear. The menu items just hang there.

I hope this image below can explain it. Has anyone ever seen this, and then know how to fix it?

Thanks!