The RIO is a single drive unit running the latest consumer kernel.

Apologies with this elementary question, but are you sure it's going into standby and not just blanking the screen? Hijack has a screen blanker and depending on how active your visuals are, the screen blank can occur at any time, depending on how long your timeout is set.

If that's not the problem, and you're actually going into standby (LED flashes, music stops playing, etc) then it sounds like a more pressing problem and I'd start talking to David @ Empeg.