Can't get ftp or webmin to work... but have phpmyadmin and wordpress ok

Hi you knowledgeable people.

Please can you help? I have ubuntu running on a virtual box on my mac. I have set up virtual directory structures and all the test html works.

I then installed phpmyadmin and that works fine. I have also setup a wodpress site on one of the domains and that works fine, except I can't update anything because of FTP.

Here's my problem. I can't get webmin to work even though I have installed it as per directions here and same with VSFTPD I have been scratching my head and trying everything I have read from google, but still nothing with these two programs.

Thanks in advance
Vince.