Yes I have checked that it is set correctly. That setting appears to not be used when generating the URLs of the reference and thumbnail images. The fix that I have done seems to work.
<?php $request = sfContext::getInstance()->getRequest(); ?> <div class="digital-object-metadata-body">
<?php if ($showReferenceCopyFileName) { ?>
<?php if ($canAccessReferenceCopy && $sf_user->isAuthenticated()) { ?>
<?php echo render_show(__('Filename'), link_to(render_value_inline($referenceCopy->name),
$request->getUriPrefix().$request->getRelativeUrlRoot().$referenceCopy->getFullPath(), ['target' => '_blank']), ['fieldLabel' => 'referenceCopyFileName']); ?>
<?php } else { ?>
<?php echo render_show(__('Filename'), render_value($referenceCopy->name), ['fieldLabel' => 'referenceCopyFileName']); ?>
<?php } ?>
<?php } ?>
and
<div class="digital-object-metadata-body">
<?php if ($showThumbnailCopyFileName) { ?>
<?php if ($canAccessThumbnailCopy) { ?>
<?php echo render_show(__('Filename'), link_to(render_value_inline($thumbnailCopy->name), $request->getUriPrefix().$request->getRelativeUrlRoot().$thumbnailCopy->getFullPath(), ['target' => '_blank']), ['fieldLabel' => 'thumbnailCopyFileName']); ?>
<?php } else { ?>
<?php echo render_show(__('Filename'), render_value($thumbnailCopy->name), ['fieldLabel' => 'thumbnailCopyFileName']); ?>
<?php } ?>
<?php } ?>
There may well be a better way of doing it.
Chris