Can't access pure-ftpd
I found the solution

1- In Lion the PAM scheme is a bit different than Leopad, the /etc/pam.d/pure-ftpd file in particular. That's why the default pure-ftpd configuration in Lion didn't work. As a quick fix, you have to:

cp /etc/pam.d/ftpd /etc/pam.d/pure-ftpd

i.e. you copy the Lions' default ftpd PAM scheme to pure-ftpd. It works.

2- For Lion, you have to install pure-ftpd-1.0.36, not 1.0.33 otherwise it hangs while trying to login to pure-ftpd.

3- Lastly, you have to set a password for the user you want to use. In my case I set for root (don't worry about the root access, the pure-ftpd is not open to Internet I use it solely inside LAN for development)

passwd root (enter any password)

Because you can set any password here, your root password can be different from the Mac OS X's user with root privileges.