FTP server - ProFTPd Not working

I've just installed Virtualmin and was unable to get ProFTPd up and running in it's default config. I edited the config file as it was looking for a non-existent DSA host key file - the service now starts, but does not work.

running netstat -aln | grep :21 returns nothing, and I am unable to connect via FTP/Telnet to port 21.

I can connect use SFTP (via OpenSSH), so theres a workaround for now - just trying to figure out why this is happening, and it's difficult as ProFTPd isn't logging anything.