I've had this happen on my korkers before. Try not baking them for as long or lower the temp. Its all trial & error. Kind of like baking a cake- what works for one person & their oven, might not work for you.
I don't bake my hairbows though, I spray each layer with hairspray & let it dry. Assemble the bow & then spray again & dry with a blowdryer on high heat.