Hey Electricians - Please help

First I would like to admit I am very weak in understanding the terminology or the science of electricity, but I am learning some things, so let's just leave it at that.

My question is this. My current system is hooked up to a Richard Gray's Power Company RGPC 400Pro. I am also using a PS Audio Humbuster to kill the DC noise in my lines (this caused torroidal hum in my amp). Everything in my system is dead quiet, so I am very pleased. However, when I turn the overhead light on and off I can hear a click through my speakers when everything is turned on. The light is a florescent light, btw. I know that the light and the consent that my gear is running through are on separate circuits, because I recently upgraded my socket and even after I turned the breaker off for the socket the overhead light remained functional. The click that I mentioned doesn't affect the sound of my system, so long as I do not turn it on or off when listening, but it annoys me just the same. Perhaps if I understand what is going on here I can either do something to fix it or simply resolve not to be annoyed by it anymore.
Please let me know if this is something you understand and can explain it to me.
Thanks!