undefined method `copy' for File:Class

I've just upgraded a project to Ruby 1.9.2 and the following line crashes the app with 'undefined method `copy' for File:Class'

File.copy(animage.image.path(:export), destfile)

I have the following libraries loaded in this module

require 'zip/zipfilesystem'
require 'iconv'
require 'net/ftp'
require 'fileutils'