Taskbar sticks up with IE

[Len]

Seems like a simple thing, taskbar set to auto hide...browsing multiple
windows with IE...then I find the taskbar is stuck up and won't go hide. I
always find a way to get it working again, by clicking on stuff but I have
no idea what causes this to happen in the first place and don't know
specifically what I do to get it working properly again. Happenes about once
or twice a day.

Thanks
Len