HMC 4.5 UR 2 has been released.

Description of Update Rollup 2 for Hosted Messaging and Collaboration 4.5

http://support.microsoft.com/?id=957584

Issues that the update rollup fixes

This update rollup fixes the following issues:

This update rollup fixes the following issues that were not previously documented in a Microsoft Knowledge Base article:

• You receive the following failure exception when you attempt to create a Resource Mailbox:
  The recipient '<UPN of Recipient>' does not have access permission to the specified resource mailbox.
• The ChangeOrganizationPlanAssignment procedure in the Hosted Email 2007 Namespace fails with an error message that resembles the following:
  Unable to create 'cn=FolderAdmins@Hostedorg...', object already exists
  This error may occur if the hosted organization uses Public Folders.
• The CreateMailbox procedure in the Hosted Email 2007 Namespace fails with an error message that resembles the following:
  E_BLOCKMODEL_NO_RANKED_RESOURCES_FOUND
• The NewUMDialPlan procedure in the Managed Unified Messaging 2007 Namespace restricts the value of the NumberOfDigitsInExtension parameter to the range of 3 to 7. The correct range is 1 to 20.
• A failure in a CreateMailbox procedure may result in inaccurate data in Exchange Resource Manager.
• The SmtpDomainCache task logs a success (0x0) status in Scheduled Tasks even if it fails.
• Some of the memory that the Exchange 2007 Provider consumes is not released as quickly as it should be.
• The health of a server may not be accurately updated by the Hosted Service Monitor procedures.