Have you tried running it off a powered USB Hub yet?
The otg controller in the TP limits "directly" connected devices to 100ma, but devices after a Hub should be able to get the full 500ma USB 2.0 Limit set by the hub. ( Touchpad -> OTG adapter -> Powered Hub -> KB/Mouse/Hard Drive ). This may not be the issue, but if that particular Flash Drive is requesting more than 100ma from the usb port, then it will have to go through a hub. Have you tried a different flash drive (my 16gb Corsair Drive works fine after the hub).