Have not heard about this problem before, usually everyone complains that their paper cups fall off after baking, lolol.
If you have a dream recipe and don't want to change a thing try some non stick paper cups.
Reynolds has them available in the supermarket bakery aisle if you want to try some without having to invest in a 100 piece sleeve.
You will recognize them by the bold print as well as the price (a bit pricey compared to the thin paper ones we were used to using).
The thickness is also a dead give away, nice and hefty for the size.
Here is a for instance link (I love the angled cut ones for muffins) http://www.countrykitchensa.com/shop/cake-decorating-supplies/cupcakemuffin-papers-standard/38/530/1089/
mimi