Yes, the exoterra's are know for such problems. I always see if it's water tight before making a viv build. You just need to empty the tank and reseal it with some 100% silicone.
As for the screen top, it's only really good for a low humidity tank. I rip out the screen as soon as I take the exoterra out of the box. I take the top to a local glass shop and have them custom cut glass to fit into the underside of the top. You can use the thinest glass available. Then just silicone the glass into the underside of the top. Now your viv is ready for your build out.
I have seven exoterras and I much prefer them over the ZooMed brand. You just have to customize them for dart frogs and they'll give you many good years of service.
