Is it the primer? I have been using a super mini 4081 and it always had a sweet taste. I am using prefilled carts and the Marlboro liquid. I only refill each cart 2 or 3 times. Or could it just be that the carts for the 901 are different? The carts that I have for the 4081 are from two different suppliers, but taste the same. Any ideas? I added a couple of drops of Wilton's but it doesn't seem to help much. Thanks!