I'm trying to set up a many to many relationship using the has_many :through method and then use a multi-select field to setup the relationships. I'm following this tutorial:

http://asciicasts.com/episodes/185-formtastic-part-2

However for some reason the form displays a strange hex number and it changes each page refresh, I'm not exactly sure what I'm doing wrong. Below is my model/view code.

company.rb

has_many :classifications
has_many :sics, :through => :classifications

sic.rb

has_many :classifications
has_many :companies, :through => :classifications

classification.rb

belongs_to :company
belongs_to :sic

_form.html.erb

<% semantic_form_for @company do |f| %>
<% f.inputs do %>
    <%= f.input :company %>
    <%= f.input :sics %>
<% end %>
<%= f.buttons %>
<% end %>

Also here is the the form looks like it's showing the correct number of entries for the field but it is clearly not showing the correct name for the relationship.