My tracking shows a 1 pound package, too! I wonder if that is a default amount and the actual amount will be put in later. I know if I send a package and don't know the weight I put in 1 pound and they adjust it later...
Which is what you don't want to do because they will ding you with an extra for changing it. You should always 1) weight and 2) measure and calculate your dim weight. Use which ever number is higher.