That's the context menu that comes up when you right-click. If you use the up/down arrow key, the various entries will highlight and using the Return key will activate the sellected/highlighted item. You can use the ESC key to dismiss it.
It's normal operation.
Settings or operation issue. Totaly benign.
Try using the other button for now.
You can also use the Tab, arrow keys and Return key to navigate around. Much slower, but it should work.
Check the mouse, or tracking/pointing device, properties, maybe the buttons are swapped.
Electro, November 2011