I don't know why this is happening!  I've been collaring my cake pans with parchment for a while now and all of a sudden now the strips on the sides rise in my pans when the cake batter rises!!!  Why is this happening?  Has it happened to anyone else and if so, how do I get it to stop??  I am totally perplexed...

Are you greasing the sides of your pan first?  I grease mine (with shortening) before adding in the parchment paper and that usually holds it in place

Yes, I'm spraying with either Pam or the Wilton Bake Off spray.  I don't get it...

maybe I'm spraying too much???

AHave you changed position in oven, or have you checked your oven temp lately? If no other variables have changed, it almost sounds like the oven is too hot, or close to a top source of heat that the cake is setting it self early to the collar, and takes the collar with it as the rest of the interior of the cake bakes and raises. If you spray the collar sides, you are almost defeating the purpose of collaring, right?