I used to have the Squirrel Buster Mini (can be seen at http://www.amazon.com/Brome-1055-Squirrel-Buster-Mini/dp/B001FK81PU/ref=sr_1_1?ie=UTF8&qid=1316525048&sr=8-1). But I changed to a new feeder (link below). Birds still use it, but nowhere near as much as my old feeder. I traded in my Squirrel Buster Mini for this new feeder. Is it that birds prefer to face forward when eating? I was thinking of attaching tubing horizontally by the feeding ports so they can do that. Any input on what I can do or what may be going on would be great. I get house finches, chickadees, and american gold finches.
http://shop.wbu.com/products/productdetail/WBU+Medium+Quick-Clean%26%238482%3B+Seed+Tube+Bird+Feeder+%28green%29/part_number=1033/567.0.1.1.25206.25754.0.0.0?pp=12&
Edit: I had this new feeder for three days now.
Edit: Thanks for the answer!
-I use the same mix, but may change to pure sunflower hearts to entice them more
-Maybe it does take some time for it to get around word of beak that this feeder is available 
-if things don’t work out, I’m tempted to go back to the old feeder
….but this one is so nice looking though!