Hi Joe, I may have found how some duplicate search results are being indexed. I was not able to test this on the demo system--perhaps the search indexing is not enabled there.
Today I edited an HTML instance, updated it, then immediately went back in and inserted some additional text, and updated again. Now, when searching on a unique term, the page is returned twice in the results, showing the first and second version of the updated text. You can see this with this search.
In case it helps with troubleshooting, we have both content versioning and content workflow enabled, and I have set the following search-related keys in user.config:
<add key="DisableSearchFeatureFilters" value="false" />
<add key="SearchUseBackwardCompatibilityMode" value="false" />
<add key="EnableSearchResultsHighlighting" value="true" />
<add key="ShowRebuildSearchIndexButtonToAdmins" value="true" />
<add key="SearchIncludeModuleRoleFilters" value="true" />
<add key="SearchResultsPageSize" value="20" />
Just let me know if you need any further info.
Jamie