It sounds to me from what i read that you have both HDMI and component cables running from the Slingbox out to the TV, which is fine. What I'm a little hung up on is what you have running from the Comcast X1 to the Slingbox. Do you have an HDMI cable, component cables, or both running from the cable box in to the Slingbox?
Also, where are you not getting video? Are you not getting video on the TV, the Slingbox, or both?
Let us know
I am running one hdmi from my X1 "slave" to a HDMI one splitter. From there I am running one hdmi cable to the TV and one to the sling box (in). Then one hdmi from slingbox "out" to the TV and a set of component cables from slingbox out to TV.
The TV does not pick up on the component cables at all (says no signal). I now get one HDMI channel that says it cannot see video from slingbox. In the "video box" I see a green screen now that flickers with a second or two of tv but stays mostly green.