Buzz - Which I can tune with the Sample Rate Slider

Cubase 6
Texas Instruments Firewire Port (not sharing the IRQ)
Intel Quad Core i7 PC
64bit Windows 7 Ultimate

When I run Cubase (and only when I run Cubase), as soon as Cubase is finished loading, I hear a very slight but ear fatiguing buzz (at about 12kHz) from my monitors AND headphone outputs on the MR816CSX.
Adjusting the sample rate and or the latency slider in the Yamaha ASIO control panel, causes the buzz to get higher or lower in pitch. Sliding it all the way left, the buzz actually turns into a pretty solid tone.

This is happening with no project loaded in Cubase at all. No plug ins, no nothing. Just a blank Cubase window.

When I close Cubase, the buzz miraculously disappears…

When I route my computer audio (for like YouTube and Windows Media Player) through the MR816CSX, there is no buzz at all. Completely silent.

What could be causing Cubase to create noise in the MR816CSX? (I have all of the latest drivers of everything, video card, ASIO drivers, Cubase, etc.)

Please help!! I’m starting to loose my mind and ears.