Postgresql – Invalid version while creating PostgreSQL 9.1 cluster

I'm trying create a cluster with existing data directory on Debian 2.6.26-2-686-bigmem. I use PostgreSQL 8.3 installed from apt-get and PostgreSQL 9.1 installed from OpenSCG I want to create cluster with existing data directory and add it to postgres-commons using command:

pg_createcluster -d /opt/postgres/9.1/data/ -e UTF8 --locale ru_Ru -p 6432 9.1 MAIN_RU

The result is:

Error: invalid version: 9.1

I found this question Can't create clusters in PostgreSQL 9.0 but it seems in my case the problem is in postresql-commons package or in PostgreSQL 9.1 package that is installed.

aptitude show postgresql-common
Package: postgresql-common
New: yes
State: installed
Automatically installed: yes
Version: 94lenny1
Priority: optional
Section: misc
Maintainer: Martin Pitt <mpitt@debian.org>
Uncompressed Size: 496k
Depends: postgresql-client-common (>= 94lenny1), procps, adduser, debconf (>=
     0.5.00) | debconf-2.0, lsb-base (>= 3.0-3)
Recommends: ssl-cert (>= 1.0.11)
Conflicts: postgresql (< 7.5), postgresql-7.4 (< 1:7.4.8-10), postgresql-8.0 (<
       8.0.3-7), postgresql-client (< 7.5)
Replaces: postgresql (< 7.5), postgresql-client (< 7.5)

Update.

I check this on Ubuntu 2.6.32-24-generic #39 with same deb packages, the problem is the same. I think it's in postgresql-commons facilities packaged in OpenSCG deb. PostgreSQL 9.1 is released 2011-09-11.