Has anyone experienced their Fan Speed on their AC's changing? If I change my Fan Speed from 3 to 4 and see it on the screen at 4 before it goes off, five minutes later when I notice it blowing more than what Fan Speed 4 should be, I hit the Fan Speed button to check, only to see that the Fan Speed is now on 5. When changing the speed slower it will aslo move one speed slower a few minutes later... I have actually kept the screen up and watched the Fan Speed change on its own. Is this a normal characteristic or operation for our AC systems??? Thanks!!