I have  a problem with transactions and I hope you can help me.

On 9.11.13 I sent only 10BTC from my computer qt wallet
 

to online wallet in blockchain


but now I see that it also sent 21.675 BTC to another adress, I see it in transaction


but I can't see it on my computer wallet and I didn't send anything to this adress.

so what is the 21.675 BTC about?