Since Postgres version 9.1 the parameter standard_conforming_strings is turn on.
It controls whether ordinary string literals ('...') treat backslashes literally, as specified in the SQL standard. This behaviour is different to verions before 9.1 and JobScheduler will throw an exception. To avoid it turn standard_conforming_strings in your Postgres configuration to off.
see http://www.depesz.com/index.php/2010/07/21/waiting-for-9-1-standard_conforming_strings-on/