Hi Steve,
One thing to try:
Change Base URL on FTP tab of Global options from http://www.leighsailingclub.org/media/results to just media/results and try uploading. The http://www.leighsailingclub.org is what I think may be causing your issue.
The Base URL is a directory/folder path and must not have web/ftp server name / IP address included. URL would probably be better replaced by word folder / directory.
Kind regards,
Huw