I have a direct tv HR21 DVR hooked up to my plasma via HDMI. I have the harmony one remote which works great except for one activity. I have an activity called listen to XM. When i hit it my TV stays off, my DVR turns on and my Onkyo SR605 turns on and goes to CBL/SAT input. I have favorite icons set up for the touch screen. When I hit one of the icons I cant get it to change the channel to that one i hit. I can use the up down channel to change it but not the icons which have the right channels programmed. Is it something with these 800 channels. I do notice when on i have the tv on and set to channel 806 i cant switch to another channel by using a favorite icon without hitting exit button on remote then hitting the icon i want. i hope i explained this well enough.

Have you tried changing the interkey delay for the HR 20 device on the Harmony One?

Try 100ms.

The activity "Favorite Channels" feature sends commands to the "Tuner" device.
1) Check your activity again and make sure you selected the correct device when it ask "which device do you use to change channels".
2) Check the "How do you select channels with your original remote?" configuration under Device > Settings > Redo initial setup for this device (or Advanced setup...)". It has 4 options (2 numbers, 3 numbers, Numbers + Enter/Select, Numbers only). Make sure the correct one is selected.

On the Harmony One, what button do you press to enter the Favorite Channels mode? On the 6xx series, you press the Media button. The Media button toggle between Favorite Channels and Current Activity mode. On my 659 and 680, pressing a button like Menu, Exit, Info, Guide, etc., while in Favorite Channels mode, will also switch the display back to the current Activity mode.

The One's LCD screen alternates between Additional Commands and Favorite Channels, using a virtual button to toggle.

Thanks