This is a problem that i'm totally stumped on. Taskbar Icons that are pinned, as well as open program thumbs keep disappearing. This is totally random, no set pattern. I've tried updating drivers for the vid card, rolling back to old drivers, nothing seems to work. I've also tried the usual uncheck hide the taskbar and recheck, changing the start menu, keeping commonly used programs in start menu, etc. This is using an add-in card which is a necessity.
Here is the specs on the machine:
New Dell Optiplex 390 i3 2100 Proc 3gb Ram, Windows 7 32-bit.
The add in card is an Nvidia 8400 GS model. I've tried different versions of the 8400gs, from MSI, or from other manufactureres and regardless it keeps happening.
After the Icons disappear, I can log out and log back in and they return, but disappear again. I can reinstall the drivers for the vid card and it fixes it for a few days, and then they disappear again. There isn't any set pattern of days that it happens, software being used, etc. This happens whether the Aero Theme or Classic is used. I've went into advanced settings and disabled all "special effects" as well.
Another user in the office had the same problem with the exact same machine, but updating the vid card drivers fixed the issue.