The steps Chad has provided would be correct, can you follow them and get back to us with a Private Message if you're still getting this signal loss message so we can set up a tech?
I have been having the same problem. I have two 722k and one 722 reciever. For the past few months one of the recievers will lose signal. Dish has sent two repair technitians out they find no issues and are telling me it is in the cables. Makes no sence to me because when I lose signal I can unplug one of the recievers that is working and the one that has lost signal regains it immediately. I would ugrade to a hopper but don't want to go through the same issue if Dish can't guarantee I won't have the same problem.