Yep, I am the exact same with Ameda for whatever reason. I can get a letdown no problem but for some reason it doesn't seem to empty me at all. I gave it a week, even trying the method Evasimone mentioned but it did not work out for me at all.
Glad you figured it out and got something that works.
Marianne, mama to L. 10/28/09 and Baby E. 2/1/13
ISO: New or EUC Planetwise hanging/large wetbags, Simplex OS, bamboo prefolds.