Are you connected to BES? I looked at the ThinkOutside site and they even mentions that BES IT Policies can block the driver installation. Also they mention that the BES admin may need to make changes to the policy to allow for third party Event Injections. Was this done (if on BES).
Have you tried the keyboard driver available from MyMobileGear
? It has been reported that it works better than what you get with the keyboard you have.