If you face the following symptoms:
- you have Lync 2013 client running on the desktop
- you have a web application with Microsoft Silverlight SDK controls embedded in it
- the controls are in enabled state but theirs GUI do not reflect the user’s current state in Lync (see MyStatusArea below)
- and no such an issue if Lync 2010 client running on the desktop instead of Lync 2013
then most probably you do not know or forgot about the new registry entries introduced by Microsoft for Lync 2013.