If you have any customers running Lync for MAC that have had problems with the VPN bug, it should now be resolved with the following update:
http://support.microsoft.com/kb/2690036
This update resolves the following issues for Microsoft Lync for Mac 2011:
· Several issues with Cisco and Juniper VPN clients
· An issue that causes an Active Directory lockout when the Kerberos protocol is used
· Several issues that cause Lync for Mac 2011 to sign out unexpectedly or to crash
YMMV