[Centos] ftp ftom outside the local network

I have Centos3.3 installed, vsftpd, apache2, ports 20&21 open on router,
firewall disabled at this time :

/etc/passwd looks like this --- ftpadmin:x:502:502::/var/www:sbin/noligin

uncommented the lines in /etc/vsftpd/vsftpd.conf :

chroot_list_enable=YES

chroot_list_file=/etc/vsftpd.chroot_list

I can access ftp from within network no problem, but using external ip it
will validate login but cannot bring up folders

Any suggestions......

This is the response I get using FileZilla (similar response using CuteFTP)

Status: Connecting to 216.201.247.147 ...
Status: Connected with 216.201.247.147. Waiting for welcome message...
Response: 220 (vsFTPd 1.2.1)
Command: USER ftpadmin
Response: 331 Please specify the password.
Command: PASS ********
Response: 230 Login successful.
Command: FEAT
Response: 211-Features:
Response: MDTM
Response: REST STREAM
Response: SIZE
Response: 211 End
Status: Connected
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/"
Command: PORT 172,17,2,12,16,230
Response: 200 PORT command successful. Consider using PASV.
Command: TYPE A
Response: 200 Switching to ASCII mode.
Command: LIST
Error: Timeout detected!
Error: Could not retrieve directory listing
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