When opening up a product page (example.com/store/women/catalog/product/view/id/215/) in a new session and using the standard add to cart, my product gets dropped and says the shopping cart is empty. However, once a ?SID= is assigned I am able to add the product to the cart. I am using Lesti::FPC.
Form action before getting an SID:
action="http://example.com/store/women/checkout/cart/add/uenc/aHR0cDovL3ByaW9yaXR5b3V0Zml0dGVyLmNvbS9zdG9yZS93b21lbi9jYXRhbG9nL3Byb2R1Y3Qvdmlldy9pZC8yMTUvP1NJRD1jYWUwNjU4ZWNiNjkxNTdjZDczMzZkNTllY2E0MmJmMg,,/product/215/form_key/Dij9pPXAwRBzAywH/?<(!)-- fpc session_id_placeholder -->"
Form action after getting an SID:
action="http://example.com/store/women/checkout/cart/add/uenc/aHR0cDovL3ByaW9yaXR5b3V0Zml0dGVyLmNvbS9zdG9yZS93b21lbi9jYXRhbG9nL3Byb2R1Y3Qvdmlldy9pZC8yMTUvP1NJRD1jYWUwNjU4ZWNiNjkxNTdjZDczMzZkNTllY2E0MmJmMg,,/product/215/form_key/Dij9pPXAwRBzAywH/
They are the same besides the fpc session_id_placeholder