Click on an mp3 file that used to work, rhythmbox comes up and appears to be playing, but no audio comes from speakers or headphone jack. Jumping forward on song sometimes produces a very brief spurt of the song. Other players play the file if brought up in 'open with', e.g., movie player. Sound on computers is otherwise normal.
The problem exists on two Toshiba Satellite laptops, one a 32 bit CPU and the other a 64 bit machine. Both have clean Ubuntu 12.04 32-bit installs with restricted extras and medibuntu. Not sure if Rhythmbox worked before the restricted extras and medibuntu were installed.
apt-get update and apt-get upgrade made no difference.
Internet search reveals only one other user reporting similar problem. Before I back it all up and reinstall 12.04 over again is there something else i should do to fix the problem?