[Exim] MajorDomo

I am setting up Majordomo to run with Exim and am hitting a slight problem.

List commands etc. work fine but I can't subscribe to any list created.
The error I get is:

** |/usr/local/majordomo/wrapper majordomo <majordomo@???>
D=majordomo_aliases T=address_pipe: Child process of address_pipe transport
returned 9 from command: /usr/local/majordomo/wrapper

Any help would be appreciated.

Ken.