Works Flawlessly on my Laptop w/ Fedora 20 and GMAMEUI. No, I do not have a powered USB hub, though I do not believe this is an issue, as the first 16 inputs work in MAME, and all inputs are recognized by the OS itself, proven by running evtest. It looks like I get the same results in AdvanceMAME as well. Not to mention that earlier, without the GP-WIZ plugged in, I had a USB WIFI dongle and Keyboard plugged in without issue. Good, high quality 1A PSU. Oh, and I get the same results after disabling the overclock.