Solved Disappearing Icons on Task Bar

On booting, I have a full taskbar. Periodically, perhaps 3/4 of the icons disappear . If I start a new program, even on top of what I am working with, the icons reappear, but they will disappear again. This seems to be a known bug, but there are no solutions that work for me. Has anyone else encountered this? I don't know how to approach the situation.

If you are running any 3rd party app that affects the GUI, check to see if there is an update for it. If so update it and see if the issue is resolved. If not, uninstall the app. This last update affected such apps as Open Shell, startisback, start11, etc

Have to eat my words. Problem resumed a short time later. "Tracked this down, at least for my system. I am using Stardock "Start 11" that site said to download the files in MS KB 502376. Working so far."

A new take on the situation: I accidentally discovered that if I scrolled down a click or two with my mouse the "missing" icons rose back into view.
I hadn't done this before applying the MS KB 502376 files, so I don't know if this was a fix or whether it had always been there.
I'll keep trying to find the issues behind this behavior, but for now it is working again. Sorry for the false leads.
Addition: I completely removed the Start 11 add-on and the taskbar is back to normal