If your pod is flipping with a heat shield attached, then a quick fix to the module is needed to fix the physics aspect of the heat shield. (Note: not my fix, all props and credit goes to Flowerchild) http://forum.kerbalspaceprogram.com/entries/3490-How-to-fix-those-heatshields!-%28get-rid-of-command-pod-flipping-into-the-heat!%29