This is a weird one. Using GNOME window manager in Linux.
If I start start a SimpleGame and hit cancel at the preferences dialog, my keyboard repeat no longer works. That is, I hold down the up arrow and I only go up 1 line. But, if I start up the SimpleGame again and hit OK then my keyboard repeat returns.
Nothing really big, but man is it annoying. 
Yes, I have noticed this as well. It’s something to do with cleaning up the keyboard and LWJGL. Long ago (year or so?) we talked with the LWJGL team about it, and did everything twe should be doing to clean up the keyboard before quitting, but it’s still present.