How to enable the esc key AS shortcuts?

OK, this is starting to annoy me pretty intensely. For some reason the esc key shortcuts are not functioning, and nothing I do seems to be able to restore them. Even ticking the ‘Esc Key Shortcuts’ option in the actions panel dropdown menu has falied to make it possible for me to do as much as type ‘esc-s-t’ to bring up ‘stop()’.

Suggestions, anyone?