Earlier we re-released the following Rollup Updates. These updates address an issue in which digital signatures on files produced and signed by Microsoft will expire prematurely, as described in Microsoft Security Advisory 2749655. Also see Security Advisory 2749655 and timestamping on the Security, Research & Defense blog.
The re-released Exchange 2010 SP2 RU4 includes the following additional fix:
2756987 Only one result is returned after you click "view all results" in Outlook 2010 or in Outlook 2013 in an Exchange Server 2010 environment
It is not required to uninstall the previous rollups to install the re-released rollups listed above.
Read my favorites blogs:
Designing a backup less Exchange 2010 Architecture
Step by step guide for upgrading Active Directory from Microsoft Windows 2003 to Microsoft Windows Server 2008
Microsoft Exchange 2010 CAS Array – Steps and Recommendations
Appear Offline in Microsoft Office Communicator Server 2007
Microsoft Exchange 2010 Test cases
Microsoft Exchange Server 2010 Disaster Recovery
Microsoft Exchange Server 2010 Upgrade Guide