There are several different names you can use for FTP connections to the "homepages" systems. For yonks, I simply used "homepages.force9.net" and was a bit bemused by posts from various people saying they could not connect to it, for I'd never experienced any such problem.
Then, one day, out of the blue, I did. Fortunately, I recalled the problems other people had posted, and was able to identify the name "ftp-proxy.force9.net". I believe there are other names you can use (some including your username?), but I've never taken much notice of them. Perhaps someone else will post details. My own experience is that "homepages.force9.net" or "ftp-proxy.force9.net" will do the trick.