Fatal error when enabling list subscription block

Hey Lev,

I tried enabling a subscription block for one of my lists and I got a White Screen of Death. Once I got the site functional again (by disabling the block in the database), here's the error message that I found printed on the screen:

Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 513 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 517 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 520 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in _mailchimp_subscribe_anon_form() (line 549 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 513 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 517 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 520 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in _mailchimp_subscribe_anon_form() (line 549 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 513 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 517 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in mailchimp_subscribe_anon_form() (line 520 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).
Notice: Trying to get property of non-object in _mailchimp_subscribe_anon_form() (line 549 of /Users/benkaplan/git/drupal/sites/all/modules/mailchimp/mailchimp.module).

Thoughts?

--Ben