Does Puppet 2.7 allow a class inheritance of an unparameterized "params" class?

I'm getting the following error when I run puppet-lint:

$ puppet-lint manifests/* manifests/init.pp - WARNING: class inheriting from params class on line 72 

I had myself a quick search on duckduckgo.com, and got this:

http://puppet-lint.com/checks/class_inherits_from_params_class/

However, our Puppet Agent versions are all 2.7 or later, and our Puppet Masters are all 3.0 or later.

For reference, the init.pp code in question follows:

class myclass ( $zone = 'top', $::myclass::params::base_url, $::myclass::params::username, ) inherits myclass::params { ... 

The code in params.pp is as follows:

class myclass::params { $base_url = hiera('myclass::base_url','https://beta.tpsreports.com/coversheets/') $username = hiera('clap::base_url','prod') } 

Even if the Hiera lookup fails, I still shouldn't be getting errors like this:

err: Could not retrieve catalog from remote server: Error 400 on SERVER: Must pass ::myclass::params::base_url to Class[Myclass] at /etc/puppet/manifests/nodes/beta_servers_0.pp:126 on node beta-web-server-0.tpsreports.com 

Now that I've hashed through some of that background, to which I'm more than willing to add, if anyone asks, my questions follow:

1. If my params class will provide parameters even if the hiera lookup somehow fails, why am I getting this error?
2. Do I have to use the horrible workaround (that is, "What you should have done" from the puppet-lint.com link, even though I have a Puppet version higher than 2.6.2 in all cases?