How to make popup volume bar linear instead of pixely box

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http://askubuntu.com – I used to have a nice sleek-looking linear popup volume slider bar like this: http://i.stack.imgur.com/DRBYY.png. Now I have a pixelly volume slider box whenever I change the volume on my keyboard: http://i.stack.imgur.com/mXva7.png How do I change my popup volume bar back to what it used to be? (HowTos)