fix #892. The spinner was never removed. In the normal case this didn't matter because the whole edit form was removed anyway. But in case of an error, the form remained visible and the submit button was not accessable anymore.

fixed by keeping track of the last spinning submit button for todos

app/helpers/todos_helper.rb

@@ -16,8 +16,8 @@ module TodosHelper
       &block )
     apply_behavior 'form.edit_todo_form', make_remote_form(
       :method => :put, 
-      :before => "this.down('button.positive').startWaiting()",
-      :loaded => "this.down('button.positive').stopWaiting()",
+      :before => "todoSpinner = this.down('button.positive'); todoSpinner.startWaiting()",
+      :loaded => "todoSpinner.stopWaiting()",
       :condition => "!(this.down('button.positive').isWaiting())"),
       :prevent_default => true
   end