Yeah Jedi has the answer. The stick you bought doesn't support MCE. If you have to use USb then send it back and try one of these
http://www.ebuyer.com/UK/product/85336/rb/19539438770
Edit: hmm yeah is does say it supports it. What graphics card do you have? ATi by any chance? Have you tried updating the drivers for your card using the latest MCE drivers?