Index: primary_term.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/primary_term/primary_term.module,v
retrieving revision 1.2.2.5
diff -u -u -p -r1.2.2.5 primary_term.module
--- primary_term.module	1 Nov 2007 16:39:43 -0000	1.2.2.5
+++ primary_term.module	25 Jul 2008 08:12:57 -0000
@@ -92,7 +92,7 @@ function primary_term_form_alter($form_i
                   // not sure why we have the line below. from old days.
                   // unset($vocab['#options'][0]);
                 }
-                $terms = $terms + $vocab['#options'];
+                $terms = array_merge($terms, $vocab['#options']);
               }
             }
           }