Keyboard works for controls, but not for input

I have just started using XBMC on my Pi, and everything that I've used it for so far works great. The only issue I'm having at the moment is with the keyboard. I'm using a wireless keyboard and mouse to interface with XBMC, the mouse works fine and I can use the keyboard shortcuts for controlling menus, etc., but I can't use the keyboard for inputing characters when I need to fill, for example a search box. I always have to use the on-screen keyboard, clicking the letters with the mouse, which is slow and a bit frustrating.
Is this the normal behaviour?
Thanks!