Glitches in Panning

Hi all,

I've been playing with the Panning in WebAudioAPI for a while. Recently I
noticed the output of a panner glitch when the position value changes from
positive to negative close to 0. Seems like the issue is more audible when
the original sample is continuous.

I created a jsfiddle to demonstrate this. I can reproduce the issue on
Chrome, Firefox and Safari on OSX to various degrees, but it's definitely
audible in all.

http://jsfiddle.net/notthetup/qWHAt/

Steps to reproduce.

1. Press "Play Tone" or "Play Ambience".
2. Wiggle the slider left and right across the 0 value.

Has anyone else noticed this? Or am I doing something wrong?

If this is indeed a bug, I'll go ahead and raise issues in the relevant
browsers.

Thanks!

-Chinmay