97 Altima power antenna

I just installed a pioneer 4500mp mp3 player on my 97 Altima. I noticed the power antenna is acting difference from before. On my old stereo system (Nissan's CD/FM/AM stereo comes with the car) , the antenna only come out when I listening to radio. Now  the antenna come out no matter if I listening to radio or CD. It will only goes back down when I turn the stereo off. Can somebody tell me if there is anything wrong with it? Did I do something wrong on the installation?

Thank You

Ben

Sometimes the pioneer wiring harness will have both a blue wire and a blue/white wire.  The all blue wire is the one you're supposed to hook up to the power antenna as it will only send its signal when the radio is turned on.  The blue/white wire will cause the antenna to stay up any time the unit is on (radio or cd), so you don't want to hook up that wire.