I recently upgraded both postgresql and slony in my environment and since doing so have been unable to get replication to start.

I am running pg 9.1.3 and slony 2.1.1

The error I get is

2012-05-31 08:42:50 NZST CONFIG version for "host=xxxxx dbname=admin user=slony port=5432 password=xxxxx" is 90103
2012-05-31 08:42:50 NZST DEBUG1 local_listen "host=xxxxx dbname=admin user=slony port=5432 password=xxxxx": backend pid = 24945
2012-05-31 08:42:50 NZST FATAL  localListenThread: "select "_gz_admin".cleanupNodelock(); insert into "_gz_admin".sl_nodelock values (    2, 0, "pg_catalog".pg_backend_pid()); " - ERROR:  duplicate key value violates unique constraint "sl_nodelock-pkey"
DETAIL:  Key (nl_nodeid, nl_conncnt)=(2, 0) already exists.

2012-05-31 08:42:50 NZST CONFIG slon: child terminated signal: 9; pid: 24941, current worker pid: 24941
2012-05-31 08:42:50 NZST INFO   slon: done
2012-05-31 08:42:50 NZST INFO   slon: exit(0)

admin=# select * from _gz_admin.sl_nodelock;
 nl_nodeid | nl_conncnt | nl_backendpid 
-----------+------------+---------------
         1 |          1 |         24546
         2 |          0 |         24918
(2 rows)

Any assistance appreciated.

Glen.