I just upgraded Winiki to MediaWiki 1.13.0. But once I had done so, the site failed with following error message:
SQL failed ... column "rev_parent_id" does not exist.
Now, it turns out that the revision table was added to MediaWiki in version 1.10.0, so it seems this was something broken since the upgrade to 1.10.0 back in November last year, but was only now being exposed. No doubt the issue has arisen because I insist on using PostgreSQL.