A HighConfidenceDisplayProperty type is mapped to two or more crawled properties that have the People category in Windows SharePoint Services 3.0. When you perform a full user profile import, the values for those crawled properties are lost.
To resolve this issue, apply the following updates:
975002 Description of the Windows SharePoint Services 3.0 Cumulative Update Server Hotfix Package (Sts-x-none.msp): October 27, 2009
975731 Description of the SharePoint Server 2007 Cumulative Update Server Hotfix Package (Coreserver-x-none.msp): October 27, 2009
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.