Hi Euan,
I've reported this problem just now to the Novell Forge mailing list. I think the server must be disconnecting before the entire file comes down.
At any rate if you want to work with the VS solution I highly recommend you get the code from svn trunk using TortoiseSVN as it is the most up to date stable code and has a lot of new work that isn't in an official release yet.
http://www.mojoportal.com/tortoisesvn.aspx
Best,
Joe