Though Dav has a good idea, I found out something odd. Going back to the terminal from the room before it, which activates the script which makes Viridian happy, the terminal in that room is fine. HOWEVER, if you immediately go to the terminal in the next room, it shows the problem that this thread is about, having Viridian's text box and squeak. Now if you go back to the room where the problem first was, then go back to the room before it, then come back to that room, the problem now is located there. (may have a detailed tutorial later...)
I think it has to do with the 'sad' command, as both times Viridian was sad when 'talking to himself'. I wonder if this is the same for all terminals? I think it works on normal mode, though I haven't tried there.