Infrared Remote Encoder/Decoder

Hello everyone,
I connected an infrared sensor to my arduino, and I looked at the signal when I press a key on my Infrared remote. I was expecting each key to have its corresponding signal; but I noticed that, for the same key the signal was different the next time you press it. I don't get it! What's happening?

Do you want to try with a few more details like for a start what remote you have, what sensor, what code you're using to show you the signals and exactly what signals you are getting from each key?

All I get from my IR remote is one code per key plus the special repeat code when a key is held down.