My cassette deck cycles(loads/ejects) without a cassette?

I have a factory bose am/fm/cd/cassette stereo in my 1997 nissan maxima. Every time I start my car, my cassette deck makes a ton of noise.... it's trying to load and eject a tape; but there is no tape! After doing this for 30 - 60 seconds the display reads "no tape."

How can i fix this? I never use cassettes so totally dissabling the cassette portion would be fine by me.