SharePoint: How to fix: Shared Services Provider creation failed (User cannot be found)

I tried creating a new Shared Service Provider, and it's giving me an error: Shared Services Provider creation failed Reason: User cannot be found.  I looked at the logs (c:\program files\common files\microsoft shared\web server extensions\12\logs), and there revealed the error.

• Go to SharePoint Central Administration > Application Management
• Go to Site Collection Administrators under SharePoint Site Management
• Update the Primary (and/or secondary) Site Collection Administrator accounts.
• Execute the following command: stsadm -o execadmsvcjobs

Verify the status of the SSP by clicking on the "Shared Services Administration" link.