Thank you for the information provided. I see you having problems connecting your Slingbox to your cable set-top box. Now, if your cable box only has 3 cables to plug in they will be composite inputs.
Composite Cables-The white is for the left audio, the red is for the right audio, and the yellow is for video. Which means that you will only have Standard Definition streaming to your Slingbox.
Component cables- Are used for High-Definition. Used with high-end video devices. These kind of devices split video colors into their components: green, blue and red. The cables carry no sound, so they're used with analog or digital audio cables.
If you want HD quality you would need to purchase a composite to component converter.
Sling Media Support