https://blockchain.info/tx/f9979da318152a9c2f7f76dbed35218088d56e0fa3f8355536b7a95b92a2b0f4
In this transaction the last address in the receiver's address is that of the sender's address.
Please Explain.
Its called change. When you receive 1 BTC in a single transaction you have to spend it entirely. Kind of like a 1 BTC bill. It can also be a 0.12345678 btc bill. If you want to spend 0.25 BTC of your 1 BTC bill you get 0.75 BTC as change (no fee for simplicity). Good wallets use a new address to receive the change. The TX you provided however was created by blockchain.info which tends to reuse the same address, thus the change is send "back" to the address the initial bill was recieved on.
Good wallets use a new address which is not backed up with your normal wallet to receive the change
there, fixed it for you
A separate backup for every time a change address is created does not sound like a good wallet to me. Mabye I missunderstood your point?