Thanks! The best part is I've got it setup where I can use one mouse for all four screens, the pro acts as the "server" and the air the "client". I can also drag a file between the two and it automatically copies wirelessly.
Some of the other members may chime in here, but It's been my experience that on models with the tear-off earstems this can happen. If you're feeling adventurous, you could tear the stems off and put them back. Sometimes this drastically reduces the squeakyness.