Optimizing sprocs
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I'd like some help in optimizing the following query:

			SELECT DISTINCT TOP (@NumberOfResultsRequested) dbo.FilterRecentSearchesTitles(OriginalSearchTerm) AS SearchTerms
			FROM UserSearches
			WHERE WebsiteID = @WebsiteID
			--AND dbo.FilterRecentSearchesTitles(OriginalSearchTerm) NOT IN (SELECT KeywordUrl FROM PopularSearchesBaseline WHERE WebsiteID = @WebsiteID)
			GROUP BY OriginalSearchTerm, GeoID

It runs fine without the line that is commented out.  I have an index set on UserSearches.OriginalSearchTerm, WebsiteID, and PopularSearchesBaseline.KeywordUrl, but the query still runs slow with this line in there.

Any other suggestions?