It appears that dnastase is doing setxkbmap as root. I don't know whether filologen and mlpmail are doing it as root as well. I did it as user. And DISPLAY was bound (which it needs to be). Depending on how you get into root, DISPLAY might not be bound.

You also need to check which device id your bluetooth keyboard is connected to. You can to that with:

% hildon-im-xkbtool --list

(again as user, not root)

For me, the device is (usually) 4 but sometimes is 5 if I connect two bluetooth keyboards and then disconnect the first one. You need to modify the -device argument accordingly.