I found this advice:
There are a few steps to solve your problem:
First thing to do is Clear items from the Office Clipboard. If the Microsoft Office Clipboard is not displayed in the task pane, click Office Clipboard on the Edit menu. On the Office Clipboard task pane, do one of the following: To clear all items, click Clear All .
Next thing is to switch off the clipboard show option. To do this, what you can do is to again display the Clipboard menu (select Office Clipboard from Edit Menu). And in the selection button "Options" at the bottom of the screen, select this particular option: "Collect Without Showing Office Clipboard"
and now, you are relieved of the bug.
Hope this helps.
here. I have the problem, but it's sporadic. I just tried the technique, and I don't see the problem, but since it's sporadic I won't know for a while if it's gone for good.