You cannot find the Double-byte Character Set (DBCS) file name from the crawled URL in a Microsoft SharePoint Server 2010 site or in a Microsoft SharePoint Foundation 2010 site.
This issue occurs because the DBCS file name is encoded in the Crawl Log page and therefore cannot be read.
To resolve this issue, apply the following hotfix package:
2276336 Description of the SharePoint Server 2010 hotfix package (osrchwfe-x-none.msp): August 31, 2010
2266423 Description of the SharePoint Foundation 2010 hotfix package (Sts-x-none.msp): August 31, 2010
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.