Service release 4.3.0 corrects an issue where use of the Today button in Staff Scheduler was causing some calendar bookings to appear blank.  This issue is described in detail in our knowledge base here:

http://trafficlive.screenstepslive.com/s/2523/m/5630/l/53489

More significantly the automated update methods in Adobe Air have changed and this version includes changes to the way in which auto update is handled. It is essential that all users accept this update before 2 March 2012 or their system will not update to Version 5.0.0,