Whever I put my MacPro to sleep, the R4 usually doesn't go into sleep mode. It can do one of several things:
1. Cycling continually between going to sleep and then immediately returning to power on and never actually go into sleep mode,
2. or . . . remains in a "on" state but the power button turns orange
3. or . . . occasionally goes to sleep.
In addition, when Shutting the computer, the drive fails to shut down and hungs up the shutdown sequence for the computer. I have had one minor event when PD2 "Command times out on physical disc" but the system immediately recovered with "Physical disc has been reset". Whenever I use the Pegasus Utility, the Dashboard shows everything is GREEN.