My understanding is that you first have to download MTX, (basically, their download/patch manager), and then get it through that mechanism. Since MekTek decided to go this route, instead of through a decent torrent mechanism, their server is a molten pile. Give them a few days to sort it out. On a related note, if you type "mektek" into Google, "mektek down" is the second option.
http://www.thenonews.com/news/game-n...eat-a-ppc.html