SharePoint 2010 - Jabber

Hello,

  Were running a Exchange 2010 farm and are trying to integrate Cisco's Jabber.  All our clients run outlook 2007/2010 and use IE 9.  Trusted sites is configured with the SharePoint site.  Some users when they log into SharePoint can see users Jabber status others can not. Does anybody know what might cause this behavior?

Thank you,