I'm assuming you have the 500? If so, you don't need a second set of cables going from the slingbox to the tv. Just the component from the cablebox to the 500. Then just use the HDMI from your cablebox to the tv.
As for the constant restarts, make sure your slingbox is not on top of your cablebox. The heat generated from your cablebox and the slingbox itself, might mess up the slingbox. Not to mention your cablebox as well, if it can't get rid of the extra heat.