1) MOSS2007 uses the “Comments” field (from Document Properties) as its description.

2) MOSS2007 does not search the keywords assigned to an Office document via Document Properties.

3) For Word, Excel and PowerPoint documents, if you search for a word that appears in the document’s description (aka the “Comments” field), then the description is displayed in the search results with the search term highlighted in bold.

4) For Word, Excel and PowerPoint documents, if you search for a word that only appears in the body of the document, then:

# for Office 2003 documents, a snippet from the body of the document is displayed in the search results, with the search term highlighted in bold. The description is not displayed, even when it exists.

# for Office 2007 documents, the description is displayed in the search results.

5) If you search for a term that only appears in the document’s “Keywords” field, then nothing is found in the search.

6) If an Office document has a title assigned in its Document Properties, then the title is used in the search results. If no title is specified, then the document’s filename (including the file extension) is used instead.

http://www.thismuchiknow.co.uk/?p=41

Havnt tried it but apparently works:

http://mysharepointblog.com/post/2007/02/Suppress-Microsoft-Office-Document-Authentication-Prompt-In-SharePoint-WSS-30.aspx