I assume you just got it back from the upholstery shop? My guess is he did not put enough padding on either the back, bottom or both. I just did mine and I only have about 1/4" gap right in the middle 4" or so. Now after thinking about it, It could be TOO MUCH padding at the front of the bottom seat, too. If you put a good layer of felt on the front rail of the spring bottom, and put too many layers of foam/cotton, then you might make the material to short at the back of the bottom and it would have a tendency to draw it down too short when you pulled it tight.