KB975995 Update Rollup 8 for Microsoft Dynamics CRM 4.0 was released on December 18th and is available for download at http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=c53b2916-6b93-4092-bdd3-a394c96ca000

Update Rollup 8 contains a cumulative set of updates and hotfixes. For more information see Article ID 975995 at http://support.microsoft.com/default.aspx?kbid=975995

Before you do anything else I’d suggest reviewing the above article in-depth.

One key thing to note is that Update Rollup 7 is now a prerequisite for deploying Update Rollup 8. Update Rollup 7 made some pretty significant modifications to CRM and especially the CRM for Outlook Client.

As always, I’d suggest doing a full backup of MSCRM. Update Rollup 8 can be uninstalled but it’s better to be safe in case the uninstall tanks. Also, I’d suggest installing this in your test environment and then testing both for server and user issues.