I'm on the laptop now.
I sent a large video file to the thumb drive (Corsair Flash Voyager GT) what I got was ~40mbps write/~150mbps read. So theres definitely something going on with yours. Maybe find an external HD to send some data to and test the speed, I think that would give you the best idea of what the read/write speeds really are.
About the problem with the drivers, what was being posted here on the forums was that the update was making the usb ports go completely kaput, as in not working at all. If yours are, I think youre fine, although the fact that the one is on the fritz is kind of troubling. Sorry I couldnt be of more help.
ROG Notebooks: G75VW, G74SX, & G73JH And a gaming rig.