'%' not working

I have ~recently switched to Mac from Linux and was looking for a config that 'just works' and so I picked this setup.

After having used it for some time, I'm finding that the '%' key doesn't work...it's supposed to do 'matchpairs' - ie if it is on a '[' it should jump to the matching ']'.

If I 'set matchpairs' is shows matchpairs=(:),{:},[:] which looks correct.

Am I missing something special in maximum-awesome that means '%' isn't the same as regular vi?