When registering each slingbox, did you use two different names? I plan to do same so two locations can watch football. In yesterday's post I was told to connect second slingbox input to the first one's component output. This is how you share one cable / satellite box. Be careful you have enough upload bandwidth as HD usually requires 8-10 Mbps upload speed and many Internet service providers have asymmetrical service with relatively low upload speed. You'll need about 20M for simultaneous operation. If using Wi-Fi vs. the much better Ethernet connection, your Wi-Fi router must also support 20M over the distance too. Suggest you do a Wi-Fi speed test using laptop at the slingbox.