META definition works intermittently

In my ion3 directory, I have my own version of cfg_ion.lua, in which I set META to be Mod4 ('Windows' key on my laptop) with
META="Mod4+"
Subsequently there are several dopath()s, the last of which is do_path("cfg_dan") which contains my personal customisations.

My problem is that the definition of META to be Mod4 does not always take effect, although I know that my version of cfg_ion.lua has been read, as my key-bindings in cfg_dan.lua (those that don't involve META) are working, implying that the dopath("cfg_dan") in cfg_ion.lua has been seen.

I've held off asking this for a couple of weeks as it seemed silly and I thought it might 'go away', but it hasn't. I've experimented with killing and restarting X, and spawning a second X session from the first one with startx -- :1 &, but have discerned no pattern so far. In particular, the lack of META binding can occur on subsequent restarts of X, even if it had been bound correctly on previous X sessions since the last reboot. One consistent observation (I think) is that I have not noticed META ever being correctly bound in my first X session after booting the computer.

What is causing this apparently non-deterministic behaviour?

Thanks a lot,

Dan

ion 3rc-20070720