There's a bug in Drupal module Panels v2.0rc1a which you may need to keep an eye out for. If you happen to be using the default_panel_minis() hook to programmatically load minipanels you won’t be able to edit or export the minipanel once it has been loaded:
The only way I’ve found to work with the minipanel from that point is to paste the exact same code from the default_panel_minis() hook into the importer. A bit of a bug, you might say.