I know there are some issues between Kunena and the Gantry framework (I know this from experience, with this site actually).
From what you wrote there seems to be a JEM problem, but just to be sure.. do you have Kunena enabled on the same page and could you disable it and test..?
Hi, from other extensions like cb I learned, always to try with the official templates (like beez 2 or 5) too. If the module is working there, then it is the problem of the special template and has to be resolved from their side.
If not, then it's probably the problem on the side of the extension.
Did you try that?
