I have discovered very very nasty bug lately. When you export the panels page and it has taxonomy argument. Settings of argument do have machine name of the taxonomy vocabulary but it ties up to vocabulary id. This means that your panels page can break pretty easy in case you will happen to have your exported vocabulary to have different id. This may happen pretty often if you use features extensively for example when develop project in 'code-driven' way. Drupal.org ticket https://drupal.org/node/2270505