Baking problems

I bake glutenfree. I mix my own breadflour, all purpose flour and cake flour. I can bake nearly everything I want, but when I bake bread, many times an airpocket forms under the top crust. Otherwise it comes out really good. Any suggestions?

Thank you, Kitchen Witch! I believe this answers my question . You have so much knowlege, I dare to ask you another question: Do you know the ingredients for a cake mix that I can use to bake some of these yummie things that start with: 1 cake mix, … (either yellow, white, choc)
I can use my own cakeflour, it is a very good mix!
Thanks again!!!

Thank you again. This will help make Christmas better!