I get this error message when editing regular menu items. I have upgraded my site from d6 to d7 and haven't had that problem in d6.

Notice: Undefined index: #parameters in _menu_item_container_form_menu_edit_item_alter() (line 86 of xxx/sites/all/modules/menu_item_container/menu_item_container.admin.inc).

A quick look into "_menu_item_container_form_menu_edit_item_alter()" reveals that the index "#parameters" is supposed to be set in the first argument $form.

Please have a look.