When mining, all my shares are rejected. Why am I not getting any accepted shares?
My guess is that you did not launch cgminer with the --scrypt option.  This is required to mine Litecoin, Dogecoin or any other scrypt coin. When mining scrypt coins that card should deliver ~100 Kh/s in your screen shot it shows Mh/s which would indicate that you are using SHA256 which is for Bitcoin.