Not sure what is going wrong.
But here are 2 things to keep in mind:
1. The old standard of username

assword@host is depreciated. It'll be supported for a long time as just some legacy thing, but it's not a internet standard way of doing things anymore. At least that is my understanding. I THINK that's right, but I can't find anything on it, so I could be wrong easily.
2. FTP is inherently insecure. It sends out your username and password in plain text in quick succession. It's trivially easy for any host between your client and your server to intercept the password and gain access to your account.
If you have a ssh account on your destination machine try using the SFTP protocol which is ssh pretending to be a FTP server. Doesn't have all the features, but suffers from none of the security flaws and works better on most networks. Will be a bit slower, of course, the encryption/decryption stuff introduces overhead and increases cpu usage. But it shouldn't be a big deal. To use that you go sftp://host/ in nautilus. You can probably setup keypairs and ssh-agent to manage the keys to make it a automated proccess, not sure.
I'd try it without the password, just
ftp://username@host and see how that works out.
Also that stuff that enables gnome's nautilus to have folders as ftp sites and such is called gnome-vfs, or gnome virtual file system. There is some command line apps that can go with it like gnomevfs-mount that may make troubleshooting a bit easier. Never messed around with them, personally, though.
Also maybe look at the gnome-keyring-manager stuff.