Hmm, tried changing the address. The address on the remote changes but doesn't change on the receiver. Even tried changing back to original address of 2 which is what the sys info screen says it is and still no luck....... Any other ideas?
Reattach the antenna. Replace the batteries (again! ). Reboot the box (just in case).
If this doesn't help, you probably have a broken remote (broken transmitter).
Call Dish (or whoever you purchased it from) and request a replacement.
If you have moved the receiver or even anything in the room it could have caused interference. Try changing the position of the remote antenna in small increments.
I had to finally make mine about 15° in order to get it to receive properly.
If the remote works sometimes it could be that the receiver is getting too hot. I have a 522 and if I don't keep a fan on it, it will get warm and the second remote will not work....but after you cool the receiver down it works fine.