Did you try a different coaxial cable? You need to verify if the issue is with the coaxial cable or the signal, so you can try to use a different cable or connect the Slingbox to another source like a DVD or a cable box to check if the issue persists. You can try to use a different Input on the Slingbox to verify if this happens not only with the coaxial configuration
I have tried connecting to my DVR and connecting directly to the cable. I have used the coaxial cable connection, the S-Video connection, and the Composite video connection. In all cases I get audio as it should be, can change channels and all is good. The issue is the screen is totally scrambled. It has a green tint, but there is nothing distinguishable about the picture at all. Any other suggestions?