Odd question, but do you have an HDMI cable running from your Genie to your TV? If you do, it is very possible the issue you are running into is HDCP, which is s copyright protection software that is only enabled when an HDMI cable is plugged in. I assume this is likely, as the original Slingbox did not transmit HD. This is a limitation of the cable box itself; all of the Genie boxes have this software immediately activated upon power-on. The only way to deactivate this would be to remote the HDMI and power cycle the Genie box. You would not be able to plug this back in without reactivating the software.
I hope this answers your question!