We came across some users who were located behind some industry-standard firewalls with NAT translation and facing issues in uploading their websites. The problems can most easily be solved by turning on passive (PASSV) FTP mode in your upload software. This option can be found in CuteFTP by clicking the "edit" button in the Site Settings window.
Please see your FTP client help for other FTP clients to find the location of this setting.
If you are still facing same problem, and you are behind a firewall, please contact your network administrator or ISP Provider.