Resolves threading issue in ChannelState.

Resolves issue in tuner controller where controller was not releasing
sourced tuner channels, preventing re-tuning to other frequencies.
Resolves issue with channel timeout on MPT1327 monitored traffic
channels

src/audio/AudioChannelPanel.java

@@ -230,12 +230,20 @@ public class AudioChannelPanel extends JPanel
 							mFrom.setText( from.getValue() );
 							updateAlias( mFromAlias, from.getAlias() );
 						}
+						else
+						{
+							mFrom.setText( "-----" );
+						}
 						
 						if( to != null )
 						{
 							mTo.setText( to.getValue() );
 							updateAlias( mToAlias, to.getAlias() );
 						}
+						else
+						{
+							mTo.setText( "-----" );
+						}
 					}
 				} );