It might not be the monitor, but you PC. When you turn your monitor off, what is the power-state of your PC? If it is asleep, it might just be a glitch resuming from that mode. If your PC is NOT in sleep or standby when this happens, then I think you are right, and it is a glitlch in the monitor's USB hub. Since it seems to come back up after you unplug your monitor from power, I am thinking it is your monitor. Have you tried a different port on your PC for your upstream cable? Have you tried a differnt port on the monitor itself? Good luck!