EAD On oct 18 2011,duplicate copy sent

[vreddy10z]

EAD undeliverble to duplicate copy sent

I applied EAD using e-file on 20 sep 2011
The activicyt changed to card production ordered
On oct 11-2011--Post office return mail as undeliverable.
I called the uscis customer service to mail me the copy
I saw the following notice today
On October 18, 2011, a duplicate notice was mailed to you regarding a decision on this case, or describing how we will process the case if it is still pending.

what this means?

[kabkaba]

I don't think it means a duplicate card has been sent. But only way to find out is to get the notice.