Hmmmm....no other reports, I don't see it...logic says to look for something that might have changed in your situation. If it were something changed at the server, everybody'd see it. That doesn't preclude a boundary condition in which something in the design is interacting with some rare combination of stuff with your setup. Let's go through some exercizes.

Is JavaScript turned on in your browser? The surest way to get the static pages is to have scripting turned off, since it's scripting that selects the Nexus when you click the Table of Contents button (it's a failsafe design: Since the Nexus requires scripting, defaulting to static is the proper response).

Do you connect through a modem, or broadband? I'm wondering if there's a timing problem such that a script file isn't arriving in time to be used.

Do you see any error messages? I'm interpreting your description to mean that this happens when you go from a message back to the TOC, so in particular, do you see error messages when the message page loads?

Problems at this stage tend to take a while to figure out, since I got the obvious ones early. Please be patient.