The problem is likely Aion. It doesn't seem to be a very friendly game when it comes to getting multiboxing programs to 'hook' onto its game clients. My guess is that you're going to need to try something more "powerful" and up to date like AutoHotKey (free, no idea if it works with Aion), HotKeyNet (free, no idea if it works with Aion), or ISBoxer (not free, but works with Aion), in order to multibox Aion.