I confirm that installing package gstreamer0.10-plugins-ugly solved the mp3 unknown time problem. After installing the package, I needed remove the files from rhythmbox and have them rescaned.
-- Rhythmbox 0.12.0 time unknown, seekbar disabled https://bugs.launchpad.net/bugs/373534 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs