Caching issues on www.unl.edu sites

We are experiencing an issue on sites that begin with 'www.unl.edu' in which sometimes the wrong page is returned at some URLs.

A stop-gap solution if you are experiencing the problem on your site is to go to admin/config/development/performance (as in http://www.unl.edu/mydepartment/admin/config/development/performance) and click the "Purge varnish cache" button. We will investigate a permanent solution.

Note that if your site is located at an address such as http://mydepartment.unl.edu/ we don't believe you are affected.