Thanks, I figure the list just isn't being rebuilt each time the gui is opened.
There's an issue with RTB_registerPref - it seems like Badspot's done something to it somewhere but changing the gamemode then making any kind of call to it results in a "Syntax error in input" which is clearly out of my control, but server prefs are basically incompatible with gamemode changes until that's sorted.
I'll be releasing another update to fix the server name/welcome message not being changed (the variable names were changed) and to re-add the colorset selection and more useful add-on selection.