Time Warner Cable remote not controlling volume or turning off box?

I have time warner cable and a marantz rc 5400 and for some reason I can't control the volume with the remote or turn of the cable box (the tv turns off but you can still hear the audio, so I have to get up and turn the box off manually). How do I fix this?

So what can you do

You aren't using the correct codes try some of the others.