I am dissappointed! Maybe the domes are too big, I went to use my new NB for only the 3rd time and had to stop. My ribs feel bruised where the plastic rims hit! Should the edges hit rib, or boob fat? :) Going nowhere at the moment!

Just go slow, and do what you're comfortable with. It will definitely get easier. At first I had to shift the cups around until I found a spot where they were between ribs (I'm very thin). Now I just pop them on and have no trouble.

What size cups are you using? You might be pumping too hard. That happens to me when I get too anxious while pumping. Are you using the rings?

Thank Jen Jen and Ann, You know what, I didn't get the rings, it didn't come with my kit! I think that is what I needed but now I am getting smaller domes with the rings. I should have just got the rings! Oh well it is already paid for. Guess it won't hurt to have the smaller ones at first.
I must say that they have excellent customer service at Noogleberry.