Thanks Doug...SharePoint Portal Server 2001 Service Pack 2A (SP2A) replaces Service Pack 2 (SP2). If you downloaded and installed SP2, please read the SP2 Update for more information.
SP2A is a cumulative service pack that provides improved server-side document management programmability for Web Parts, updates based on the Microsoft Trustworthy Computing Initiative, and the latest fixes for issues reported by customers. To expedite the download process, SharePoint Portal Server SP2A is divided into five parts. All five parts are required. It is strongly recommended that you install SP2A on all your SharePoint Portal Server servers.
New features in SharePoint Portal Server SP2A include:
Web Storage System security fixes
Web Storage System memory fragmentation fix
Server-side PKMCDO* stability/scalability for Web Part scripting
OLE DB Provider for Internet Publishing security fixes
Download: SharePoint Portal Server Service Pack 2
News source: SharePoint Home