There was no change in the networking code, as far as I know. We added servers for the terrain data, but since they download fine in the browser, it should be ok in game as well.
Full data should not make it download anything. If they do, it could mean two things - they aren't placed in the right location (C:\Users\Simon\Outerra\data\earth\...), or the checksums are wrong when read from the disk for some reason (antivirus, disk error ...) and the program tries to re-download them.