I have just replaced a 510 with a 512. The 510 was sitting next to my 722. I have the remote addresses set on the 722 to 1 and 5 and the address on the 512 is 6. Problem is, the 722 IR remote changes the channel on the 512 even though they don't have the same address. The 512 remote doesn't affect the 722. I have confirmed that the addresses on the remotes are also 1 5 and 6. Why is the 722 IR remote affecting my 512? I ended up putting black paper over the IR sensor on the face of the 512 and am using an extra UHF remote, but I still don't understand why I had a problem. The two units are next to each other because I have a 4 channel RF generator running the 3 signals from the 722 and 512 to the rest of the house.