I have been using Fugu for years. Now my web host has changed to key authentication. I had to created a .ssh/id_rsa.pub file and copy that to the server as "authorized_keys". Now Fugu gives me the error message "Permission denied (publickey)". If I connect to sftp.wholeo.net or wholeo.net I get the same error. Once I got it to ask me for the passcode and still got the error, but I can't repeat that.
As an alternative I use Fetch and it does SFTP now OK. I prefer Fugu GUI and I don't want to buy Fetch. What can I do?
My host server is successfulhosting.com by the way.