Mapping Midi Keyboard to Ableton 7 Issues

I have mapped a number of keys on my Yamaha PSR-170 to trigger different things in Ableton Live 7.

My issue is that although the mapping works correctly, the notes are actually played from the keyboard although through the software and out of the speakers.

Example - I hit my Low EQ kill and when I hit it again, the note from the key sounds.

I have tried all the obvious solutions. Turned the master down on the keyboard, played with the preferences in Ableton etc.

Any suggestions?

Thanks.