Can't get output in Nuendo 4

Hi, I can't seem to get any sound from the MIDI keyboard in Nuendo 4. I've read the install instructions for Cubase (which is very similar to Nuendo) but still no luck. I'm using the Bome's MIDI translator pro trial and setting the Bome MIDI input to (none) and the output to (M Audio Fast Track Pro). Likewise in Nuendo, i'm setting the input to Bome's MIDI translator 1 and output to M Audio Fast Track Pro. The device window in nuendo recognizes the ethernet MIDI input, and everything seems to be set up correctly, but there's no output. Is my setup flawed? What am I doing wrong? Thanks.