The usual answer to this is to blame any other sources of infra-red i.e lights etc or you've conected it to your network and someone else is changing channels for you
I've never had this problem but I do find it ignores commands when it feels like it. It can be fussy on where you point the remote. I use a Harmony One so I cant say how the real remote works but I have had cases of going the menus when it does decide to to go back to the programme I'm watching.