Index: contrib/emvideo/emvideo.module
===================================================================
--- contrib/emvideo/emvideo.module	(revision 194)
+++ contrib/emvideo/emvideo.module	(working copy)
@@ -273,6 +273,19 @@
   $ret = emfield_emfield_field($op, $node, $field, $items, $teaser, $page, 'emvideo');
   if ($op == 'presave') {
     foreach ($items as $delta => $item) {
+      // Remove empty fields
+      if (empty($item['embed'])) {
+        // Remove thumbnail files
+        if (module_exists('emthumb')) {
+          // see http://drupal.org/node/393490#comment-1328368
+          if (is_array($item) && !empty($item['emthumb']['emthumb']['emthumb']['emthumb']['file'])) {
+            _emthumb_file_delete($item['emthumb']['emthumb']['emthumb']['emthumb']['file'], $field['field_name']); 
+          }
+        }
+        unset($items[$delta]);
+        continue;
+      }
+      
       $duration = emfield_include_invoke('emvideo', $item['provider'], 'duration', $item);
       $items[$delta]['duration'] = $duration ? $duration : 0;
     }