I installed a couple of days ago Ubuntu 12.10 (64 bit).

I today tried ripping a CD in the MP3 format.

However, whenever I try to rip, it says it is missing an extra multimedia plugin "Gstreamer extra plug-ins (i386)".

I then try to install the :i386 version of the gstreamer-ugly plugins, but then I get the same problem but with the id3-demuxer (or something similar)

The Terminal output I get from both problems (but replace the "MPEG-1 Layer 3 (MP3) encoder" with the "ID3-demuxer" name) is:

james@clefairy:~$ rhythmbox

(rhythmbox:24122): GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT (object)' failed
Rhythmbox-Message: Missing plugin: gstreamer|0.10|rhythmbox|MPEG-1 Layer 3 (MP3) encoder|encoder-audio/mpeg, mpegversion=(int)1, layer=(int)3
/usr/lib/python2.7/dist-packages/gobject/constants.py:24: Warning: g_boxed_type_register_static: assertion `g_type_from_name (name) == 0' failed import gobject._gobject

It doesn't help that each time I have to install/remove the entire Gstreamer-ugly collection each time - I can't find that specific file.

The CD plays fine, it's the ripping plugin that doesn't seem to work.

I didn't have this problem previously on 12.04 (64 bit).