At least some of us would have faced issue with Blackberry device sending duplicate messages which are connecting an Exchange 2010 SP1 RU3 environment. Upon receiving the bug report, the download link for RU3 was removed from the download site and the exchange team was working with RIM to identify and fix the issue.
Microsoft has confirmed that and they have released the new version V3 of Exchange 2010 SP1 RU3, which has the fix for the above scenario.
Download it here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=413b8979-76b8-4be4-a18b-015d025eb368&displaylang=en
Tips for the installation:
If you have already installed the RU3, it is not necessary that you have to uninstall. You may go ahead with the installation of RU3 (v3) without removing the existing R3. Others can simply follow the installation wizard.
But, follow below steps those who are running Forefront Security for Exchange.
Disable Forefront Security ( ‘fscutility /disable’ )and enable it(‘fscutility /enable’) after the installation of RU3 (v3). If you don’t follow these steps, you will have trouble in starting Information Store and Transport services.
Ref – Microsoft Exchange Blog