Your panels will indeed become slightly warped after a few uses. This is normal and to be expected. However, you may find that your tabs do not align as easily as they did when new. You can most often lightly bend the panels to re-align the tabs so that they will connect once again. This side-effect of heating the steel can be regarded as a benefit. You’ll find the warped panels often lock much tighter than they once did, making your assembly more sturdy.