Some things to try before trying another update:
Make sure you can get the 101 satellite fairly strong in your receivers meter screen, you should have strengths in the high 80s-90s, as this is the satellite the downloads come from.
Unplug the reciever from the wall for 5 minutes or so, then, plug it back in, rerun installation setup to completion, make sure you select the correct type of dish (Round if you have the dual lnb, or Oval/Triple if you have the 3lnb (for HD and internationals), etc, then retry the update.
If all that fails, and you have more than one receiver, try swapping that one out for the one your trying to update, maybe it is the cable running to that one receiver.