Here is what I have gotten back since my last update...
Sent 1 card 6/15/12 - Rec'd 1 card signed 7/26/12
Sent 2 cards 6/19/12 - Rec'd 2 cards signed 7/18/12
Sent 2 cards 3/3/12 - Rec'd 1 card back signed (he kept the second card but I don't mind) 7/19/12
Sent 1 card 7/14/12 - Rec'd 1 card signed plus he wrote a note on my LOR and sent it with the card