My verizon remote keeps switching the Cable HDMI source to Roku's HDMI

I just installed ROKU and everything works perfectly.  Except when I want to watch Verizon Cable tv, I push any button on the remote and it automatically switches the Source input from Verizon HDMI 2 to the Roku's HDMI 1 and shows the start page.  I switch the source back to cable (HDMI 2) and try again-busy any button on the verizon remote and it happens again.  Some how its taking input from both remote.  I did try to see if I could navigate the roku pages with the verizon remote and it does not work - only activates the roku to switch the source input.  - thanks