File_column issues

I am having some strange issues with file column today. This goes
back to something that I was working on before and successfully have
it working on my development box however it is not working on my
staging machine.

I have a dynamic_dir action set up for file_column that is called via
the :store_dir => :dynamic_dir

the action is this:

def dynamic_dir
File.join(“data”,“files”,self.user_id.to_s,“image”)
end

This works perfect on my development machine however when I loaded
the code up to our staging machine (getting ready to go live with it)
I keep getting the following error:

ArgumentError (dynamic_dir’ is not an instance method of class File):

like I said this works on my dev box but not on the staging machine.
The difference between the two boxes are that my dev box is a
PowerBook while the staging system is Fedora Core 4. The tmp files
are getting created however the main files are not. Any thoughts?

Andrew