I have had the same experience as lotusguy. When I contacted Dish, the first level of support tried the usual...reset the receiver, reset the sling box, etc. When I told them I had tried all of that, they passed me on to 'broadband support', but they really did not have any ideas at all. They just told me the same thing that the error message was already telling me...that I could not connect to the receiver.
This is a strange problem. The sling works fine when I am away from home. It works every time on the first try with both my laptop computer, and my iPhone4. However, when at home, on my own internal network, it almost never works with either my laptop computer or my desktop computer... but it works every time with my iPhone4 (at home on my internal network). I have tried connecting to someone else's sling box with my desktop computer, and that also works with no problem...so the same computer that does not work on my own internal network does work remotely. (Strange that it works with a system several states away from me, but it won't work with my own receiver that is only 30 feet away).
My internal network works fine for everything else. I have a Western Digital media streamer and I have no problem streaming videos, music, and photos from my desktop to the WD device. Also, my desktop computer can view my DVR contents and the Program Guide contents with no problems, and I can program my DVR, add a recording, and erase things I have already recorded with no problems.
At home, my laptop has only connected to the sling adapter once (in about 50 tries). When it did connect, it worked fine with bitrates as high as 8000K. At home, my desktop computer connects once in a while (very rarely). When it does connect, it works fine with bitrates over 8000K.
I really appreciate the help that TG2 and pabeader has given me. Thanks a lot guys! My 722k has not downloaded the new firmware yet (L686), so I am hoping that that will solve the problem, but I am not counting on that. I have run out of ideas. I wish I knew what the problem was.