You might run mythdatabasefill from a terminal...
but I dunno why it would have "just stopped working" and complained about the db... can I see an actual output or screenshot?
2012-11-26 09:43:13.639 MythTV database schema is old. Waiting to see if DB is being upgraded.
2012-11-26 09:43:14.639 New DB connection, total: 2
2012-11-26 09:43:14.641 Connected to database 'mythconverg' at host: localhost
2012-11-26 09:43:14.646 No current database version?
2012-11-26 09:43:15.656 No current database version?
2012-11-26 09:43:16.667 No current database version?
2012-11-26 09:43:17.678 No current database version?
2012-11-26 09:43:18.693 No current database version?
2012-11-26 09:43:18.701 Timed out waiting.
2012-11-26 09:43:18.701 Not allowed to upgrade the database. Skipping backup.
This version of MythTV requires an updated database. (schema is 1254 versions behind)
Please run mythtv-setup or mythbackend to update your database.
Database Host: localhost
Database Name: mythconverg
2012-11-26 09:43:18.775 Incorrect database schema
2012-11-26 09:43:18.776 DataDirect: Deleting temporary files