Here is my setup:
Cablebox #1 to Sling using component audio and Video
Cablebox #2 to Tivo using coax (second cable box so I can Tivo a different channel than is playing on the TV). Tivo uses Red, White, Yellow out to TV.
If I try coax from Tivo to Sling, it seems to bypass the Tivo and the Sling acts as a tuner (i.e. not letting me control the Tivo)
That only leaves S-Video and Digital Audio out of the Tivo. The Tivo digital audio out is the square Toslink optical jack. The Sling digital in is the round RCA type jack. I purchased a converter that will convert Toslink to RCA digital audio. However, when I hook to the sling, I see video fine, but no sound.