Template error when deploying to host with frozen gems

Hi,

I'm having some issues with deploying my app to my host server
(Dimension Servers). I froze the gems (Instant Rails 1.2.3) on my
local server and have the app running flawlessly boh on my machine and
on a few other development machines. After deploying to the host, I
get the following error on one of my views. Note: I'm using
attachment_fu, which I don't imagine could have anything to do with
this...

Any help would be much appreciated!

ActionView::TemplateError (Expected /home/yourhome/public_html/beta/
current/config/../app/models/product_image.rb to define ProductImage)
on line #2 of app/views/products/show.rhtml:

products/show.rhtml:
1: <h2><%= @product.name %></h2>
2: <div class="product_image"><%= product_image_url(@product) %></div>

Helper:
def product_image_url(p)
    # Generate URL for product images
    return p.product_image.nil? ? image_tag("/noimage.jpg") :
image_tag(p.product_image.public_filename)
  end

product_image.rb model:
class ProductImage < ActiveRecord::Base
  has_one :product
  has_attachment :content_type => :image,
                 :storage => :file_system,
                 :resize_to => '320x200>'

  validates_as_attachment
end