Active Resource without Formatters

I have installed the ExtensionlessFormat plugin but I am still not able to get the information I need from the resource.

The resource has a RESTful API that looks like this:

GET {host} /processdefinitions A list of process definitions are returned

As you can see they are expecting me not to supply the format in the URI hence why I installed ExtensionlessFormat plugin.

When I instantiate the resource and perform a .find(:all) method I get the following error:

pd = ProcessDefinitions.find(:all)
NoMethodError: undefined method collect!' for #<Hash:0x24315b4> from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.2.2/lib/active_resource/base.rb:597:in instantiate_collection’
from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.2.2/lib/active_resource/base.rb:574:in find_every' from /usr/local/lib/ruby/gems/1.8/gems/activeresource-2.2.2/lib/active_resource/base.rb:517:in find’
from (irb):2

If anyone has any advice concerning this matter, thanks for the help in advance.