Environment is REE(2011.12) on rvm, rspec 2.8.0, rails 3.0.6, and pg 0.13.2. Using PostgreSQL 8.3.17 on CentOS 5.6. The db:migrate have work correctly. But rspec have got follow
Just hit this same error, nothing worked but dropping and re-creating the database, this fixed it for me.
rake db:drop db:create db:migrate