Erratic Behavior of System Tray

This is my issue: When I boot the computer, all of the icons that I require
appear in the system tray. There's no problem there (in the beginning). After
using the computer for about an hour or so, some of the icons disappear from
the system tray, and go into "hide" mode.

Now, I have set the "Properties" (by right-clicking on the task bar) of
these icons to "always show." So, I would assume that the icons that I have
set to "always show" will do just that. But, that is not the case.

For whatever reason, some programs in the system tray have had their
property settings changed. I.e., when I right-click on the task bar to look
at the "Properties" that I have originally set up for the icons, the settings
have changed from "always show" to "hide when inactive."

This only happens with some of the icons at any given time. But the problem
has happened to all the icons in the system tray at one time or another.

Does anyone know why this is happening? Thanks, so much, for your help in
this matter.
--
Wade Terry