You can debug this type of problem by dumping the %INC variable to make sure your package is coming from the file you think it is (as Corion has pointed out):
use warnings;
use strict;
use Data::Dumper;
require 'Config.pm';
print Dumper(\%INC);
This is the first time I have worked with packages so I assumed the problem was some scoping issue I didn't understand. Hopefully I'll be able to read the signs more clearly next time. Thanks guys