Sounds like the hidden delegate rule still might be forwarding those requests. Someone with full access to that mailbox can delete the delegate rule with the free MAPI Editor tool from http://www.microsoft.com/downloads/details.aspx?familyid=55FDFFD7-1878-4637-9808
-1E21ABB3AE37. Complete instructions in the mfcmapi.doc included with the download.

Signature
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
> How do I stop receiving Meeting Requests for a calendar I am no longer a
> delegate for?
>
> I had them remove me from their Calendar but I still receive all their
> meeting requests...