on the site they have many links to different programs so i am unsure which you where trying to download.
Since i am not sure which one you wanted, i tried the njstar communicator. and i was able to retrieve it.
You might have problems with ftp servers, so try to make sure you retrieve the file from a http server, such as
http://www.simtel.net/pub/dl/59391.shtml
if you are running a firewall. it might deny you access to a ftp server.