A. Is "Legacy USB support" enabled BIOS? I find enable is best - If you disable that you won't get in to BIOS, without a PS2 kybd or resetting BIOS.
B. Do you have "Selective USB suspend" disabled in the Windows power options, of your current power profile? Have you tried enabling it?
C. Different kybds are different, try a different one.
Nice kybd by-the-way. We have two Filco Majestouches. It says CherryMX, but doesn't say what color CherryMX. I like Blue, my wife has the brown model. I like the "clicky" feel.
Oh yeah, it isn't a PS2 plug, is it? Are you using the PS2 adapter, or straight USB?
i7-3930K; Asus RIVE; G.SKILL Ripjaws Z 4x4GB DDR3 1866; MSI 7870 2GD5/OC; Crucial M4 SSD 256GB;
Corsair 1000HX; Corsair H100, 4x Excalibur 120mm PWM CPU Fan p-p, AS5; SB X-Fi Titanium Fata1ity Pro;
Dell U2412m IPS 1920x1200; Cooler Master HAF 932 case; Tripp-Lite OMNIVS1500 UPS fully Line-interactive.
(EVGA site: )

And I have a second (wife's) computer,
Eve.Overclocking is useless to me if it is not rock stable.