I should also mention that this action is a bit of a hack because Windows does not allow us to set the input for speech recognition...
I know, very stupid. Bad microsoft, bad.
The only way to change the input for speech is to change the default TTS input device, and I am doing this through the registry... (always a last resort).
Not only does this method require me to access different keys depending on which engine you are using (old or SP) and possibly with different keys for 32 bit or 64 bit machines (can't remember right now), but the keys may also have changed from Windows 7 to Windows 8!
So, hopefully you can sympathise with me on this one, but I should check that you are using the regular desktop engine and not the SP engine.