Korg M3 AND Vsti in Cubase?

Hi everybody,

Recently I have bought an audio midi interface (m-audio fasttrack c400) as I planned to add Vsti to my korg m3 workstation sounds. My goal is to use virtual vst instruments as well as the sounds from my korg in cubase for recording and editing. I have connected my M3 to my audiointerface via midi in/out and line inputs, my audio interface to my monitor speakers and to my PC.

This setup works for my vsti which, when I play notes on my keyboard are triggered and played through the speakers. If I add a MIDI channel to play my M3 sounds via MIDI I cannot here anything.

Any idea what I am doing wrong?