I hate when that happens! I usually spray my cupcake papers and pan with a little Pam, just to make sure they won't stick as much, or at all.

Happy cupcaking!

Did you just take the cupcakes out of the oven? i find that letting them sit in an airtight container (or just tightly sealed with plastic wrap) overnight softens the grip of the cake on the paper. :) Good luck!

Most cupcake liners aren't coated so it's normal for them to stick. More fat should make them release more but the never come off clean.