When you crawl the content sources on a Windows Server 2008-based computer or on a Windows 7-based computer that is running Windows SharePoint Services 3.0 or Microsoft Office SharePoint Server 2007, an index corruption occurs if there is a power outage on the computer. In this case, the following event is logged in the Application log:
Event Type: ErrorEvent Source: Office Server SearchEvent Category: Content index server Event ID: 4138Description:An index corruption was detected in component ShadowMerge in catalog AnchorProject.
To resolve this problem, apply both of the following updates:
970948 Description of the SharePoint Server 2007 Cumulative Update Server Hotfix Package (Coreserver.msp): June 30, 2009
970946 Description of the Windows SharePoint Services 3.0 Cumulative Update Server Hotfix Package (Sts.msp): June 30, 2009
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.