Executei o Totem pelo terminal e deu isso:
** (totem:6282): DEBUG: Init of Python module
** (totem:6282): DEBUG: Registering Python plugin instance: YouTubeH264+TotemPythonPlugin
** (totem:6282): DEBUG: Creating object of type YouTubeH264+TotemPythonPlugin
** (totem:6282): DEBUG: Creating Python plugin instance
** (totem:6282): DEBUG: Init of Python module
** (totem:6282): DEBUG: Registering Python plugin instance: YouTube+TotemPythonPlugin
** (totem:6282): DEBUG: Creating object of type YouTube+TotemPythonPlugin
** (totem:6282): DEBUG: Creating Python plugin instance
Traceback (most recent call last):
File "/usr/lib/totem/plugins/youtubeh264/youtubeh264.py", line 117, in on_starting_video
mrl = "
http://www.youtube.com/get_video?video_id=" + urllib.quote (youtube_id) + "&t=" + urllib.quote (re.match (".*[?&]t=([^&]+)", location).groups ()[0]) +"&fmt=18"
AttributeError: 'NoneType' object has no attribute 'groups'
demux_wavpack: (open_wv_file:127) open_wv_file: non-seekable inputs aren't supported yet.