Microsoft has released Update Rollup 4 for Exchange 2010 SP2 deployments.
To apply this update rollup, you must have Exchange 2010 SP2 installed. Remove all interim updates before you apply this rollup. The required services are automatically restarted when you apply this rollup.
This update rollup fixes the issue of having to disable & enable Forefront before & after the installation.
Download the rollup here
Check the description to know more about the issues fixed by this rollup.