I have a problem with SharePoint search not re-indexing a file after it has been modified.
For example I have a document which used to have the text testing12345
in the document so if I searched using that name I would find the document.
However I have now modified the document and removed testing12345 for the document saved it and since re-indexed the site.
Despite doing this performing a search for testing12345 it still finds my original document even though it no longer has and references.
So to summary:-