Just opened my project and clicked the nearest piece of code calling a sub. Deleted the opening ( to get the tooltip which came up fine. Hit ctrl for the faded to the point of not able to read tooltip and it faded fine. Hit again to return to normal and solid black box. Hit again to fade and it faded. Hit again to bring back and black box. Did the same thing with 3 other pieces of code showing the tip correctly then getting a black box when bringing back.
On the 3rd one I decided to see what happens when I click the tooltip. It stayed black, but when I opened a tooltip on another piece of code it now displayed/faded/returned properly like that reset something.
One other interesting thing to note is that when a tooltip is clicked the Titlebar and Menu at the top flicker like they are being repainted. Tooltips are really just a yellow window/label and usually will either close on click, stay on click, or pass the click on to the window underneath. Usually a timer times out the tooltip too, so either it has to be overrode, the tooltip is subclassed, or it is a custom control. There shouldn't be anything repainting unless the click gets passed to the window/IDE below and it goes nuts and does something.