UA-1X: SYMPTOM: Updated to OSX 10.3.3 but not receiving a stereo signal
Apple has recently updated the Core Audio driver to work better in OS X 10.3.3 or later. If you are not receiving a stereo signal, please be sure to check with your software application to be sure that it is in fact sending a stereo signal to the UA-1X. The volume control in the Apple Sound control panel is adjusting the volume of both channels, but if you only are receiving signal on one side, you will of course only hear a change on the side with existing signal.
It is possible that your application may have a pan control that has been altered.
Please install any updates for the recording software you are using for playback or recording.