No sound

Building then 'boom' no sound in till restart game

also part of the console after quit game:
Client>
Client> SoundSystem shutting down...
Client> Error in class 'SoundSystem'
Client> Command thread did not die!
Client> Ignoring errors... continuing clean-up.
Client> Error in class 'SoundSystem'
Client> Problem during Library.cleanup()!
Client> Ignoring errors... continuing clean-up.
Client> Author: Paul Lamb, www.paulscode.com
How to get the bug:

1.Build
2. might have to speed build eg place blocks fast