OK, the thing MOST likely to go wrong is the midi channel. Make sure that the track sending the CC data is sending to the same channel that the Voiceworks receives on.

also make sure that another track isn't using the same channel... if so, the last track overwrites any patches etc set by the first track.

Having established that, also make sure the voiceworks is connected to the sequencer and you are getting midi data (Lights flashing? Chords changing on the little screen if you are using a chordal patch?)