Yeah - I had read that and did comment out the gs.apple.com entries, and still had it fail two more times. But I am guessing that because I had jailbroken, saved SHSH blobs and whatever else on the iMac, something got hinky in there.
So, with that explanation of the 1013 error, that means that you can't update (assuming you've downloaded the .ipsw update file already) without being connected to the internet (?).
So, with that explanation of the 1013 error, that means that you can't update (assuming you've downloaded the .ipsw update file already) without being connected to the internet (?).