Lync Server 2010 Hotfix KB 2493736
http://www.microsoft.com/en-us/download/details.aspx?id=11551
This cumulative update improves the reliability, stability, and performance of Lync Server 2010
Lync 2010 Hotfix KB 2912208 (32 bit)
http://www.microsoft.com/en-us/download/details.aspx?id=25055
Lync 2010 Hotfix KB 2912208 (64 bit)
http://www.microsoft.com/en-us/download/details.aspx?id=14490
This cumulative update resolves the issues that are described in the following Microsoft Knowledge Base (KB) articles:
2918040 A contact is displayed with incorrect contact information in Lync 2010
2918041 Lync 2010 continues to sign out and sign in every 30 minutes
2918043 The text that describes the play/pause button is not displayed on the screen in a video call or a video conference in a Japanese, Korean or Chinese version of Lync 2010