Microsoft has release rollup 1 for CRM 4. KB952858 can be downloaded here.

This upate is for Microsoft Dynamics CRM 4.0 Server, Microsoft Dynamics CRM for Microsoft Office Outlook, and Microsoft Dynamics CRM 4.0 E-mail Router.

Please note that if you have customized Microsoft Dynamics CRM 4.0 Help files, back up your customized files before you install this update !!!