More than likely, your TAB key for entering the config menu got
changed to some other key....
I've run into this a few times when kids messed around
with all of my buttons on my control panel... its not a pretty thing.
I now use a certain 'combination' of buttons to get to the config
menu....
Im sure there is an easier solution, but I ended up wiping
out the .cfg file that stored the button settings and re-set
the buttons up from scratch....