Help get this topic noticed by sharing it on Twitter, Facebook, or email.
We do for all of our applications for the most part - the reason why deadmau5 doesn't have one on his stream is due to a bug in the flash client. There is a audio transformation that happens when adjusting the volume and for Macs without hardware acceleration for Flash (note: this is not the same as hardware acceleration - a lot of HW acceleration chip sets aren't supported by flash until flash 11.4 comes out this year).
This was put in to place to help out those users, so sorry for the inconvenience! Will need to increase the amperage of your sound output some how - you can sometimes increase the amperage in the settings of advanced sound cards.
INFLUXIS Senior FMS engineer