KB 940848 - A hotfix rollup package is available for Microsoft Management Console (MMC) in Windows Server 2003, in Windows XP, and in Windows Vista

Your one stop for MMC 3.0 updates can be found in KB 940848. It is especially important for SCCM deployments because earlier versions had a knack for crashing your console without warning.

It is available for XP, Server 2003 and Vista.

You can download the update here.