pg_createcluster failing on Trusty

Hi
I'm trying to run pg_createcluster on Ubuntu Trusty 14.04 LTS, but initdb is failing. I've installed the below packages and then run the "pg_createcluster 9.3 main" command as root.
$ dpkg --get-selections | grep -v deinstall|grep postgpostgresql installpostgresql-9.3 installpostgresql-client installpostgresql-client-9.3 installpostgresql-client-common installpostgresql-common installpostgresql-contrib installpostgresql-contrib-9.3 install
root(at)xxxxxx:# pg_createcluster 9.3 mainCreating new cluster 9.3/main ... config /etc/postgresql/9.3/main data /var/lib/postgresql/9.3/main locale CError: initdb failed
$ lsb_release -aNo LSB modules are available.Distributor ID: UbuntuDescription: Ubuntu 14.04.1 LTSRelease: 14.04Codename: trusty

Has anyone else hit this problem or know what might be causing this?
Many thanks.