I tried to watch a DVD last night, but found that I could not navigate the menu on the DVD disk -- the UP and DOWN buttons did not workI have run into a problem though, if I attempt to navigate a Bluray menu, using the internal BD handler up/down buttons only work very intermittently/slowly.
Now I had deliberately changed the mappings for UP and DOWN when displaying fullscreen video in order to eliminate another quirk, but that change disables menu navigation on DVDs
But the good news is that I have found a solution to this

I will perform some more testing over the next few days, and update the zip file in post 36 in due course.
-- from CyberSimian in the UK