sounds like the copy/paste clipboard
If you ignore it three times, it should go away.
Here's what I got from the help file:
If you close the Clipboard toolbar three times consecutively without clicking the Paste All button or any of the collected items on the toolbar, the toolbar will no longer appear automatically. To show it again, point to Toolbars on the View menu, and then click Clipboard. You can also show it again by copying an item two times consecutively.