I'm in the US, in New York, and I'm having an identical problem at my office. We have multiple bonded T1 lines here, but the download stalls repeatedly at 996-998Mb, and seems to try to resume at 986Mb. I've tried resetting the app store (which I hate with a passion) and wish I could just download the .dmg from some other source. We do not have restrictions on large file transfers with our ISP - we are regularly moving multi Gb files via FTP, DropBox, Hightail and other services, so I don't see why the crappy app store shouldn't be able to handle a download either.
I seem to recall I had this problem with the last OS too. I think I had to download the OS at home, on my laptop, make a .dmg, copy that to dropbox, and then wait for it to transfer to this computer. I'd take it to a mac store and have them deal with it, but I'm not unplugging this beast box - not a reasonable way to get service.
Anybody have any ideas why this might be hanging up, and what to do about it?