Q: how do you migrate wiki server from one ML server to another

My installation of ML server has gone a bit funny, profile manager isn't working properly so I have done another fresh install, but I would like to transfer the wiki server across.

I have tried using apples support doc http://support.apple.com/kb/HT5082 :

Copying all wikis from one OS X server to another

1. On the source OS X server, perform this command in Terminal as an administrator in order to dump the Postgres database to a file:sudo pg_dump --format=c --compress=9 --blobs --username=collab --file=/tmp/collab.pgdump collab
2. Copy /tmp/collab.pgdump from the source server to /tmp/collab.pgdump on the destination server, then copy the contents of /Library/Server/Wiki/FileData on the source server to /Library/Server/Wiki/FileData on the destination server.
3. Log in to the destination server as an administrator and execute the following commands in Terminal to ensure correct ownership and permissions, start the Postgres database, populate it with the data dumped from the source server, and finally start up the wiki service:

sudo chown -R _teamsserver:_teamsserver /Library/Server/Wiki/FileData

sudo chmod -R +a "www allow read" /Library/Server/Wiki/FileData

sudo serveradmin stop wiki

sudo serveradmin start postgres

sudo rake -f /usr/share/collabd/server/Rakefile db:drop

sudo createuser -U _postgres -d -s collab

sudo createdb -U collab collab

sudo -u _postgres pg_restore -d collab -U collab --single-transaction /tmp/collab.pgdump

sudo serveradmin start wiki

Seems to work untill you get to the part which wipes the current database:

sudo rake -f /usr/share/collabd/server/Rakefile db:drop

which throws an error message, so does anyone know the correct proceedure for ML