HELP!!! Harmony 890 problems with Denon AVR 790

So i am having issues with my Harmony 890. I have programmed it so that the up/left/down/right button is in conjunction with the Denon remote. The issue is that everytime I press the button, the Denon receiver responds as if I had pressed the Denon remote twice (i.e. if I press the down button once, on the OSD the highlight move down twice). I am using the RF extender with this because everything is in a media closet. How can I make this stop? It extremely difficult trying to program/set-up the receiver. PLEASE help!!!

Thanks!