Drive/Serpentine Belt Squeals

2001 Nissan Maxima, 83000 Miles, 3.0L motor, Auto Trans

I recently changed my alternator and drive belt. The belt was adjusted and two weeks later it is squealing. I adjusted it again and it still squeals.

Also when the car is idling the a/c compressor is rattling very loud. The air conditioner still pumps out cool air. I am not sure if the pulley is seized or not.