Active Record, PostgreSQL and Sequence Naming

If you use PostgreSQL to back your Active Record models, you should check the current names for your tables and their sequences. Prior to Active Record 3.2.7, renaming a table did not rename the associated sequence for the table’s primary key.

See blog post for details. http://www.thekidds.org/blog/2012/07/27/active-record-postgres-and-sequence-naming/