When using totem-video-thumbnailer with a *.flv video, totem-video-thumbnailer test.flv test.png I get a large amount of these errors (totem-video-thumbnailer:14346): GStreamer-CRITICAL **: gst_mini_object_unref: assertion 'mini_object != NULL' failed (totem-video-thumbnailer:14346): GStreamer-CRITICAL **: gst_event_parse_seek: assertion 'GST_IS_EVENT (event)' failed This is also a problem as the log files /var/log/messages and user.log get very big: several hundreds of MB for each new video on the system. When using it with an *.avi video, it works perfectly without errors.