Microsoft yesterday released update rollup 8 for Microsoft Dynamics CRM 4.0 (KB 975995).
You can download it at the following location,
http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=c53b2916-6b93-4092-bdd3-a394c96ca000
The KB article contains the installation instructions and list of fixes.
http://support.microsoft.com/kb/975995