222 installation question

[davemich]

A friend had an eastern arc 222 installed at their home 2 daqys ago. The tech installed both TV1 and TV2. Everything worked fine when he left. Next day my friend could turn on and off TV2 with the Dsih remote but could not change channels or turn off tuner with the remote. Again, it worked fine when he left the day before. He came back and changed the remote address for TV2 and the system is now working again. What may have caused this and could it happen again? Thanks you in advance.