[rspec-users] WillPaginate::Collection not detectible in assigns?

[lardawge]

I am transitioning a Rails 2 app to Rails 3, Rspec 2 and have several
controller where I test collect.should
be_an_instance_of(WillPaginate::Collection). The spec fails with
"expected [object] to be an instance of WillPaginate::Collection". The
class of the object in the controller is WillPaginate::Collection.
What am I missing? Why is assigns not returning the actual object?
Controller collection class is WillPaginate::Collection. Spec
collection class is an Array.

Thanks,
~Larry