Just to make it easy for you to try out or your devices are comunicating;
Go to windows - control panel - multimedia -
-midi - choose midi out as the midi output..
then load a standard midifile in the windows
mediaplayer and playback the midi.
(as you have a clavinova I suggest you load a straight piano file)
if no sound from your clavinova there's something wrong with your midi out.
You did not specify which SB live you have.. are you using the add on card with the mini-midioutputs ? or are you using the joystick/midi interface output???
Fred