Bug#436986:

[Marcus Lundblad]

gnome-media-common is already installed on both machines.
And what's strange is that the media profiles are visible in Gconf
editor: /system/gstreamer/0.10/audio/profiles
There there is the following profiles: aac, cdlossless, cdlossy, mp3,
voicelossless, voicelossy.

And this is the same on both machines. So there must be something else
conflicting or something like that...