Thanks for reaching out. Two possibilities come to mind when reading this thread. Can you confirm that you've checked these?
- Many DirecTV receivers are set to Radio Frequency (RF) mode. This setting will need to be changed to IR to work with the Slingbox. This KnowledgeBase article will help with changing that setting: http://support.slingbox.com/get/KB-5000351.html
- The IR emitters on the Slingbox 500 may not be reaching your receiver. You may want to try to use the included IR emitter cable to see if it yields better results. This KnowledgeBase article has more information: http://support.slingbox.com/get/KB-5000042.html
Product Manager @ Slingbox
Well, that's the problem: my DirecTV set top box is set to RF mode. The problem is that I will have to return the Slingbox 500. I have a projector that is in a different enclosure than the set-top box so RF mode makes this all work. Why was the Slingbox designed this way? Why can't the Slingbox work in RF mode? $300 is a lot of money for something without key features.