After recent changes in Jamendo’s streaming service, it’s no longer possible to seek forward nor backward in playing time of their Vorbis streams using Totem. VLC however lets me seek just as before. Also, seeking does work if I opt the stream as MP3.
My main desktop is an up-to-date Lucid, and I’ve also reproduced this in a virtual Maverick.
Set up: have Jamendo stream using external player, with Vorbis+m3u or Vorbis+xspf. Associate said playlist format with Totem. Start streaming, try to skip time within the playing track.
I’ve found an upstream bug which seems related: https://bugzilla.gnome.org/show_bug.cgi?id=629212#. I didn’t link it straight away because I’m not sure if it’s the exact same one as this.