I see some unexpected (for me) behaviour on Liquibase 2.0.3.
I added the precondition to a changeset with custom sql code and provided rollback for it. On HSQL the changeset isn’t run but it tries to roll changes back.
I found some similar posts like http://forum.liquibase.org/topic/preconditions-and-custom-rollback. And seems the issue is still alive, no?