Sharepoint 2007 - .mht files do not show up in search results

Question

I have a bunch of .mht files in the document library and they don't seem to be indexed.

I have checked - .mht is in the File Types list in Central Sdmin -> SSP and also there's an entry for it in the DOCICON.xml.

But .mht files are still either not being indexed or do not show up in the search.

How can I fix this?

Thanks!