I had problems when I was trying to setup a settings form for my custom modules which contains multiple editor fields.
I solved it by appending the name of the field to the editor id when fields are generated within
So in case field type is editor, I replaced the line :
$editor_id = 'flrich' . time();
$editor_id = 'flrich' . time() . '_' . $name;
In this way we ensure that all editors will have differnt ids.
I did the same for code editor field.