C.W.
I used the Vent Aire with the 2nd (& last) child, around the time they were first coming out or so. My daughter is 7 yrs old now, so it's been awhile. But I had the leaking trouble back then as well. It's rather disappointing to know they haven't improved that! I'm afraid I don't know what to tell you about that bottle, clearly they haven't changed the problem over the years. What I did was to switch back to the type of bottle I had used with my first daughter. It's the bottle that has the bent part about 3/4 of the way up. It's called "Health Flow", & it's by Johnson's. But I never had trouble with that type bottle at all, no bottom pieces to remove like with the Vent Aire, just the usual nipple and ring to remove for cleaning.