Resuming after sleep in Windows 7 causes USB keyboard to disappear

Solution 1:

I have the same problem on Linux (Ubuntu). In fact, it has nothing to do with your OS or hardware. It's N-KEY Rollover's fault. Using it over USB involves some dirty trickery, and not working after resume is part of that.

In other words, the fault is in the keyboard, and probably the only way to solve it, is to not use it over USB (but then other things won't work...).

Some info regarding this: http://www.overclock.net/t/491752/official-mechanical-keyboard-guide

EDIT:
I recently discovered a workaround to get the keyboard working after resume, without having to unplug and replug it in: it is sufficient to just plug anything into its USB hub, and the keyboard should start working. At least in Ubuntu it works, not sure about Windows.