Mine is different to this brand (it is one I have to 'pump up') however I did have trouble with it the first time after we washed it. I found that the problem was the seal around the inside rim wasn't sitting properly and therefore the vaccum (?) seal was not present. I think I was tightening it too hard and pushing the rubber piece out of place. When I made sure that the seal was sitting in the gap properly I screwed the lid on again but not too tightly and I haven't had any trouble with it since.