Index: server/Slim/Music/Artwork.pm
===================================================================
--- server/Slim/Music/Artwork.pm	(revision 16744)
+++ server/Slim/Music/Artwork.pm	(working copy)
@@ -89,7 +89,7 @@
 
 	while (my $track = $tracks->next) {
 
-		if ($track->coverArt) {
+		if ($track->coverArtExists) {
 
 			my $album = $track->album;
 
Index: server/Slim/Schema/Track.pm
===================================================================
--- server/Slim/Schema/Track.pm	(revision 16744)
+++ server/Slim/Schema/Track.pm	(working copy)
@@ -301,15 +301,14 @@
 		}
 	}
 
-	# kick this back up to the webserver so we can set last-modified
-	if (defined $path && $path ne 1) {
+	
+	if (defined $path) {
 
 		$self->cover($path);
 		$self->update;
 
-		$mtime = (stat($path))[9];
-	} else {
-		$mtime = 0;
+		# kick this back up to the webserver so we can set last-modified
+		$mtime = $path ne 1 ? (stat($path))[9] : (stat($self->path))[9];
 	}
 
 	# This is a hack, as Template::Stash::XS calls us in list context,
@@ -336,7 +335,7 @@
 sub coverArtExists {
 	my $self = shift;
 
-	return defined($self->coverArt);
+	return $self->cover || defined($self->coverArt);
 }
 
 sub path {
Index: server/Slim/Web/Pages/BrowseDB.pm
===================================================================
--- server/Slim/Web/Pages/BrowseDB.pm	(revision 16744)
+++ server/Slim/Web/Pages/BrowseDB.pm	(working copy)
@@ -474,7 +474,7 @@
 			&& (defined $params->{'album.id'} || defined $params->{'age.id'})
 		) {
 
-			if ($firstItem->can('coverArt') && $firstItem->coverArt) {
+			if ($firstItem->can('coverArtExists') && $firstItem->coverArtExists) {
 
 				$params->{'coverArt'} = $firstItem->id;
 				if (!$firstItem->album->artwork) {
Index: server/Slim/Web/Pages/BrowseTree.pm
===================================================================
--- server/Slim/Web/Pages/BrowseTree.pm	(revision 16744)
+++ server/Slim/Web/Pages/BrowseTree.pm	(working copy)
@@ -151,7 +151,7 @@
 
 		push @{$params->{'browse_items'}}, \%form;
 
-		if (!$params->{'coverArt'} && $item->coverArt) {
+		if (!$params->{'coverArt'} && $item->coverArtExists) {
 			$params->{'coverArt'} = $item->id;
 		}
 	}
Index: server/Slim/Web/Graphics.pm
===================================================================
--- server/Slim/Web/Graphics.pm	(revision 16744)
+++ server/Slim/Web/Graphics.pm	(working copy)
@@ -168,6 +168,8 @@
 
 					return ($cachedImage->{'body'}, $cachedImage->{'mtime'}, $inode, $cachedImage->{'size'}, $cachedImage->{'contentType'});
 				}
+			} else {
+				$log->info(" cached image not usable because 'orig' undef");
 			}
 		}
 	}
@@ -441,16 +443,19 @@
 	}
 
 	if ($cacheKey) {
-	
+		
+		my $imageFilePath = blessed($obj) ? $obj->cover : 0;
+		$imageFilePath = $obj->path if $imageFilePath eq 1;
+		
 		my $cached = {
-			'orig'        => blessed($obj) ? $obj->cover : 0,
+			'orig'        => $imageFilePath, # '0' means no file to check mtime against
 			'mtime'       => $mtime,
 			'body'        => $body,
 			'contentType' => $requestedContentType,
 			'size'        => $size,
 		};
 
-		$log->info("  caching result key: $cacheKey");
+		$log->info("  caching result key: $cacheKey, orig=$imageFilePath");
 
 		$cache->set($cacheKey, $cached, "10days");
 	}