Cubase AI5 not detecting instrument..

I just got Cubase AI5, along with a Yamaha AUDIOGRAM 3, and I’m trying to give it a test run, but when I try to record, nothing happens. The software isn’t picking up any sound from my instrument. I have everything connected properly. When I put the disc in to open a tutorial project, I couldn’t hear anything from that file when I tried to play it back. Are the two problems connected? Please help!

http://www.steinberg.net/forum/viewtopic.php?f=25&t=10051