logged in users don't get signed up for campaign from permalink

[mikefantini]

Steps to reproduce:

• go to permalink as an authenticated user who isn't already signed up for the campaign
• click sign up

If the user is already signed up for the campaign, the functionality works as expected.

[angaither]

The contents of the entire permalink page arecache_set as html, this was causing the dosomething_signup_form and the login||signup form to not respond.
Maybe we can try adding that in with JS?
Or perhaps we need to set the cached data to a serialized array of all of the vars that are loaded and still call the theme function on the variables.