I'm sorry you're having problems. Unfortunately, I have no way of testing the PPC builds, but the x86_64 should work and it sounds like a local configuration problem.

Make sure you have the necessary gstreamer packages installed and that they are the latest version. This sounds like you are missing the proper plugins. The standard ones are the following:

gstreamer
gstreamer-plugins-good
gstreamer-ffmpeg
gstreamer-tools
gstreamer-plugins-flumpegdemux
gstreamer-plugins-bad
PackageKit-gstreamer-plugin
gstreamer-plugins-base
gstreamer-plugins-ugly

"bad" and "ugly" and the most important for playing licensed media such as mp3's.