Impossible for module to uninstall correctly

Fresh install of:
Organic Groups 5.x-7.3
Views 5.x-1.6
OG Forum 5.x-2.2

Here is the problem: After enabling OG Forum, I simply disable it and then uninstall it. Pretty simple. Upon uninstalling, I get the error "There was an error removing the OG Forum database tables or variables." I look at the database and see the tables have been removed, just like they should be. Then, when I look at the uninstall code in og_forum.install, I see this conditional:

if(variable_del('forum_default_name') && variable_del('forum_default_container_yn') && variable_del('forum_default_container') && variable_del('forum_allow_public')
  && variable_del('forum_all_public') && variable_del('forum_auto_public') && variable_del('forum_limit'))

After consulting my bible (the drupal api), I noticed that the function variable_del does not return a value. This means that the first statement in the conditional is run (variable_del('forum_default_name')), does not return a boolean TRUE, and the conditional fails. The $vardel variable is not set to TRUE which ultimately triggers the error message explained above. This also means that only the first of the 7 variables is actually deleted.