Recently the stage 1 hipp formula I have been buying seems to have changed taste completely. It smells really foul, quite rancid, not like it did before. I have bought two other boxes of a different batch which are also horrid. I have emailed hipp who assure me that there has been no change in formulation. Has anyone else noticed a change. Is it OK? I don't really want to give it to my baby as it smells so odd.