Figured out that the xml data files are missing a broadcast/bibl/ref element with a target attribute, which is what the xslt uses to get the name of the media file. Added that to the test file (accf1), uploaded that to the eXist db on lettuce and the standard view, search, bookmark and download functionality now works. Let Catherine and Marie-Claude know.
This structure:
<recording type="video">
<date value="2006-08-28">28 aôut 2006</date>
</recording>
must be replaced by this structure:
<recording type="video">
<date value="2006-08-28">28 aôut 2006</date>
<broadcast>
<bibl>
<ref target="media/accf1.mov">Les Accents par Jean Olivier Héron</ref>
</bibl>
</broadcast>
</recording>