That's good to hear. I need to mess with it and see what's going on. Just thought it may have been an known issue since they sent 2 o rings with it. The sides of mine are bulging out as well. But I've had a few poly cells and they all seem to bulge out a little.
Sometimes I'm thinking about investing in the al box that goatbuilt sells.
Then I wonder if it really is an issue that needs addressing.