Comment 13 for bug 25632

Bug confirmed on Hardy Heron...

I found a workaround for this issue: create a file .asoundrc in your homedirectory containing:

pcm.!default {
   type plug
   slave {
        pcm "spdif"
        rate 48000
        format S16_LE
    }
}

It initiates a route for PCM into spdif plugin (I guess). Then, both test with speaker-test should work:

speaker-test -D spdif -c 2
speaker-test -c 2

These is no really a solution, because the bug is still there but a workaround that works for me.