Anyone figured out what those numbered buttons are that appear under the station ID in the media player when playing radio? Sometimes there are none, sometimes two (1 and 2), and sometimes three. Could this be an override to force use of one of the three antennas? The function isn't obvious from the results of punching them, at least not to me... I've searched owner guide and manual, and all over this site, and I haven't found anything, so posting a thread. Any insights appreciated!