PostgreSQL primary (sequence) key issue (Ruby/Rails)

["Andrew Madu" <andrewmadu@xxxxxxxxx>]

Hi Guys,
I'm completely stumped with this one!

I've included ActiveRecord::Base.set_sequence_name in my environment.rb, and
in my user.rb I've placed the following code:

class Usertbl < ActiveRecord::Base
   set_primary_key "user_id"
   set_sequence_name "seq_user_mytable"
   validates_uniqueness_of :userpassword, :username, :scope => :user_id
end