Have a look at the following wiki; http://wiki.rubyonrails.org/rails/pages/SingleTableInheritance, specifically the 'note' part.* "Note:* Rails must ‘see’ the file containing the STI classes before it can use them, otherwise you’ll end up with a “uninitialized constant” error. This can be a problem if the name of the class and the name of the file defining it are not the same, e.g. you have the model ‘Manager’ in the file ‘employees.rb’. Rails will not be able to divine the filename from the class name in this case."
I take it that this is what is biting you
Josh Kieschnick wrote: