cocos2d/cocos2d-x — pull request #2091 by jsambuo (2013-03-03 17:25:49+00:00)
Title: fix for SimpleAudioEngine::playEffect() and playBackgroundMusic() playing twice on linux

On linux, calling SimpleAudioEngine::playEffect() would play the sound effect twice.
SimpleAudioEngine::playBackgroundMusic() also had the same issue.

This should resolve issue #689