March 19th saw Microsoft release a new hotfix rollup package (build 4.0.3684.2) for Forefront Identity Manager (FIM) 2010. The official documentation for this build can be found on the Microsoft support website under KB article kb2819338. Download link is here.
This update supersedes kb2750673 (4.0.3644.2). The update contains a new version of Microsoft.MetadirectoryServicesEx.dll (126.96.36.199) and also sees the Exchange Provisioning fix introduced in FIM R2 build 4.1.3419.0 back ported to FIM 2010.
As with the previous updates to both FIM and FIM R2 please pay particular attention to the known issues in this update section that describes adding the required binding redirect statements to the configuration files that could not be patched (the installer won’t update the configuration files if you have modified them, which is ascertained by a comparison of the modified timestamp).