I am an installation specialist. Your problem comes from improper installation. Vinyl siding HAS TO MOVE! A 12' panel will expand/contract AN INCH between the heat of summer and the cold of winter. If even 1 nail is to tight and/ or the nails are not in the center of all the nail hems, then it wont move;hence, buckling. Also, after every course is installed, you must "look down the row" to make sure it is straight. Uneven subsiding requires more careful attention!