The glass door had been installed wrong. I fixed it. I also checked carefully for sagging, bowing, and used a level--everywhere. This is a very solid TV stand, we believe much stronger than many commercial aquarium stands.
My husband and I will be gambling on not having a 36 gallon flood for the time being. This is a very big gamble as it is on the second floor of our home.
That being said, we still plan to get a new stand some day soon.
And thanks again for your advice.