You guys have me worried. I just bought two more packs of 5lts of XTOL. I have used it for the last 8 months without a problem & I am just about as far from Rochester as can be. I do however develop for longer than the published times (+5%) and use it at at 1part XTOL 2 parts water. I do not know if this has an effect on the product but I mix XTOL at a higher temperature than reccomended & store it in one of those colapsable plastic bags in a box that come full with cheap wine!! I have also stored Microphen this way & it has been good after 3 months. BTW Delta 400 is possibly the best all round B&W film ever produced.(posted 8471 days ago)