1965cutlassragtop

so i replaced the top cylinders in my 65 cutlass convertible, and while in the process of priming the motor pump, somehow the drivers side frame rails bent!! really bad!! i am assuming that it happened while the top was folding down, but i can't figure out why. i bent them back so the windows would at least roll up correctly and the piece looks straight now, but i can't figure out why it happened. now i'm afraid to put the top down again cuz i don't want it to bend again. all the linkage is hooked up the same as the passenger side, so i'm at a loss. has this happened to anyone else? is there anywhere i can buy used convertible top frame parts? any ideas or suggestions would be greatly appreciated, thanks!!!!