Karen - the instructions for mine say to plug it in and reheat before placing the crusts and filling them (so yes, you have to work quickly, have everything ready). If you started all cold, it may be an issue of how much filling, or how deep the pies were. I made peach and apple pies a couple of weeks ago, with cans of pie filling, and my last batch did not have quite as much filling as the others - the tops did not puff to the top of the machine, so it didn't brown like the others. Another possibility - did you close the lid completely and lock it, and did you open it part way through to check on the pies (that might have let heat from the front ones escape)? I did that with mini quiches the other day, and noticed they didn't cook quite the same.