--- app\models\issue.rb	2013-01-20 22:05:33.000000000 +0200
+++ app\models\issue.rb	2013-09-18 09:33:10.000000000 +0200
@@ -581,14 +581,22 @@
     user = new_record? ? author : current_journal.try(:user)
 
     required_attribute_names(user).each do |attribute|
       if attribute =~ /^\d+$/
         attribute = attribute.to_i
         v = custom_field_values.detect {|v| v.custom_field_id == attribute }
-        if v && v.value.blank?
-          errors.add :base, v.custom_field.name + ' ' + l('activerecord.errors.messages.blank')
+        if v 
+          if v.value.is_a?(Array)
+            if ((v.value.count == 0) || ((v.value.count == 1) && (v.value[0] == "")))
+              errors.add :base, v.custom_field.name + ' ' + l('activerecord.errors.messages.blank')
+            end
+          else
+            if v.value.blank?
+              errors.add :base, v.custom_field.name + ' ' + l('activerecord.errors.messages.blank')
+            end
+          end
         end
       else
         if respond_to?(attribute) && send(attribute).blank?
           errors.add attribute, :blank
         end
       end