Scratch doesn't close audio device after usage

[sascha_silbe]

After playing a sound, Scratch doesn't close the audio device and even  keeps streaming audio data to the device. Apart from wasting energy, it also prevents other Activities from using the audio device, at least on some hardware (including XO-1.75).

[pgf]

this command can help observe that the activity is doing the right thing:

    while sleep 0.1
    do  
        egrep 'closed|state' /proc/asound/card0/pcm0p/sub0/status
    done

the output should be "RUNNING" while noise is being made, and "closed"
when not.