I am NO expert but a comb honey new bee. I found that few if anyone or anything I read explains how to prepare the frames- and I too had the foundation just drop out not understanding why. Most everything I read talks about the condition of the colony and how to cut. You have to secure the comb in the frame some how depending on what type of frame you use. Hence, the little magic wax melting tool that drips and melts in the foundation to the frame groove- (hint I have since learned to use clean wax) or in my case, a small paint brush did the trick. Or you use slotted top frames which I will try next year. See MP's talk on the subject including these details on the video here: https://www.youtube.com/watch?v=nIjiInZRxrQ
Linda also has something on her website, this is the link to cutting, but she also has something on how to prepare the frames. http://beekeeperlinda.blogspot.com/2007/07/cutting-and-boxing-cut-comb-honey.html
The video is much more comprehensive and offers options.
I pulled my first 2 boxes of comb this year. Some is still wavy, but you have to start somewhere.