Comment 2 for bug 435674

"""In Slony-I version 1.0, this would only lock the tables in the specified replication set. As of 1.1, all replicated tables are locked (e.g. - triggers are removed at the start, and restored at the end). This deals with the risk that one might request DDL changes on tables in multiple replication sets."""

So this is unfortunately expected behavior and throws a spanner into our upgrade procedures.