Must Press Clear on Console before GUI buttons work

Probably an easy setting someplace I missed but can't find it in forums either.

When I start my game in the Game window, there is a GUI that comes up fine. When I click on a button I get no result - it treats it as if the GUI wasn't there. It does the regular mouse action defined in my player controller script rather than the button.

If I press clear on the console, however, then I can click the GUI one time. It does what its supposed to do, but then it goes back to not working again. I need to click Clear every time I want to click a button in the GUI.