Several months ago, for an unknown reason, I couldn't use any FTP softwares. I've tried WS_FTP and some freeware FTPs, but I couldn't connect to my FTP server.
At that time, I was greatly helped by web-based FTPs. I knew 2 such sites but this is my personal favorite:
www.web2ftp.com
It can upload zip files and extract it automatically -> I like this feature.