Lost Polymorphic Associations in development environment causes delegate :blah, :to => to fail

Hi All

I have been struggling with this issue for a long time now. And before
I began to describe the problem its important to know that this
problem happens only in Development environment.

I am using Rails 2.0.2, here are my associations

class User
  has_many :comments
  has_one :profile, :as => :profileable
  delegate :email, :to => :profile


First call to comment.user.email works just fine the associated
profile object gets loaded and the delegation occurs just fine.

However, a second/subsequent call to comment.user.email throws
ActiveRecord::ConfigurationError: Association named 'profile' was not
found; perhaps you misspelled it?

The solution I have tried are and none have worked are

1). put a require_dependency 'models/profile' in environment.rb
2). put a require 'models/profile' in models/user.rb
3). put a load 'models/profile.rb' in models/user.rb
class User

def before_initialization
Profile.find(1) #just to load the Profile class, I know this looks
stupid and desperate


The only solution that works is

config.cache_classes = true #in development.rb

but as you know this is not acceptable.

Any ideas, what might be causing this bug and how I can fix it.