Often while attempting to connect to ftp, I receive the message 'Unable to connect to remote host' on the 1st attempt only. I am able to connect on the 2nd attempt without changing address or login credentials.

I also have vendors which need to place files up to the ftp and they have the same problem on the 1st attempt.

Is there a setting within Network Solutions ftp manager which needs to be changed?

It is normal for our servers to do this. The first connection attempt is blocked as a security measure. You should be able to configure your FTP client to automatically retry the connection.