Part of the setup should ask you what setting to have the tv on to watch - and you would make it the same for both - i.e. so it doesn't change anything.
In the TV setup menu, you may be able to skip unused inputs. I found it helped when setting up my 555. The simpler the setup the easier it is for the remote to control. Do this and Juzzie Wuzzie's advice and you should be sorted.