When I have combined items on the Taskbar I am unable to switch between them by clicking on them. I don’t get a preview of the windows. e.g If I have multiple instances of Explorer open and I click on Explorer in the Taskbar I don't get any menu or previews of the windows. This makes it so I can’t maximize any minimized windows without using alt-tab. This will happen with any combined items no matter the program. The issue fixes itself after a reboot and usually only appears after an undetermined period of time when the computer is locked and then unlocked. It seems like something is failing after the computer has been on for a while. Setting taskbar items to never combine negates this issue as a temporary fix but I would really like to figure out why I can view or switch between my combined items.
I am using Windows 7 Ent 64 bit on a Dell 6430u. This is also happening with other 6430u's in the company. All of them imaged with MDT and the latest drivers from Dells website.