This bug is still present. Firefox 3.0.1 on Ubuntu Hardy. 

john@roadwork:~$ dpkg -l "*totem*" "*gstreamer*"
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name                                   Version                                Description
+++-======================================-======================================-============================================================================================
ii  gstreamer0.10-alsa                     0.10.18-3                              GStreamer plugin for ALSA
un  gstreamer0.10-audiosink                <none>                                 (no description available)
un  gstreamer0.10-colorspace               <none>                                 (no description available)
un  gstreamer0.10-esd                      <none>                                 (no description available)
ii  gstreamer0.10-ffmpeg                   0.10.3-6                               FFmpeg plugin for GStreamer
un  gstreamer0.10-fluendo-mp3              <none>                                 (no description available)
ii  gstreamer0.10-gnomevfs                 0.10.18-3                              GStreamer plugin for GnomeVFS
un  gstreamer0.10-lame                     <none>                                 (no description available)
un  gstreamer0.10-plugins                  <none>                                 (no description available)
ii  gstreamer0.10-plugins-bad              0.10.6-5                               GStreamer plugins from the "bad" set
ii  gstreamer0.10-plugins-bad-multiverse   0.10.6-1                               GStreamer plugins from the "bad" set (Multiverse Variant)
ii  gstreamer0.10-plugins-base             0.10.18-3                              GStreamer plugins from the "base" set
ii  gstreamer0.10-plugins-base-apps        0.10.18-3                              GStreamer helper programs from the "base" set
ii  gstreamer0.10-plugins-good             0.10.7-3ubuntu0.1                      GStreamer plugins from the "good" set
un  gstreamer0.10-plugins-good-doc         <none>                                 (no description available)
un  gstreamer0.10-plugins-really-bad       <none>                                 (no description available)
ii  gstreamer0.10-plugins-ugly             0.10.7-3ubuntu1                        GStreamer plugins from the "ugly" set
ii  gstreamer0.10-plugins-ugly-multiverse  0.10.7-1                               GStreamer plugins from the "ugly" set (Multiverse Variant)
ii  gstreamer0.10-pulseaudio               0.9.7-2                                GStreamer plugin for PulseAudio
ii  gstreamer0.10-tools                    0.10.18-4ubuntu1                       Tools for use with GStreamer
un  gstreamer0.10-videosink                <none>                                 (no description available)
ii  gstreamer0.10-x                        0.10.18-3                              GStreamer plugins for X11 and Pango
ii  libgstreamer-plugins-base0.10-0        0.10.18-3                              GStreamer libraries from the "base" set
un  libgstreamer-plugins-pulse0.10-0       <none>                                 (no description available)
ii  libgstreamer0.10-0                     0.10.18-4ubuntu1                       Core GStreamer libraries and elements
ii  libtotem-plparser10                    2.22.3-0ubuntu2                        Totem Playlist Parser library - runtime version
ii  totem                                  2.22.1-0ubuntu2                        A simple media player for the Gnome desktop (dummy package)
ii  totem-common                           2.22.1-0ubuntu2                        Data files for the Totem media player
ii  totem-gstreamer                        2.22.1-0ubuntu2                        A simple media player for the Gnome desktop based on gstreamer
un  totem-gstreamer-firefox-plugin         <none>                                 (no description available)
ii  totem-mozilla                          2.22.1-0ubuntu2                        Totem Mozilla plugin
ii  totem-plugins                          2.22.1-0ubuntu2                        Plugins for the Totem media player
un  totem-plugins-extra                    <none>                                 (no description available)
un  totem-xine                             <none>                                 (no description available)
un  totem-xine-firefox-plugin              <none>                                 (no description available)