also I got some coin confirmed on Account Balance.
It's difficult to say if the payout is accurate but shares count [paid and updaid] is 90% of what I submitted with cpuminer
cgminer (or whatever miner you use for LTC) also uses some CPU resources to coordinate the GPU-work. If you mine both YAC and LTC (or some other cgminer coin), you're going to see some loss of hash-rate on both (though still better results than only mining one coin of course).
I only see 0.7% loss hash rate on gpu, I am happy to ignore it if I can mine yac