This might be a stupid mistake but it made me headache all night long. I made the FTPES testing on ProFTPD on Ubuntu 8.04, in order to access from the internet, then I have to configure MasqueradeAddress to the domain name that can resolve to my WAN IP address from outside. But If I set MasqueradeAddress, I will have the problem on FTP Layer in all CMS, Joomla, Wordpress. The CMS will show the error message that it cannot find the correct path of the editing file, etc. If included the wordpress auto updating problem, I had this problem few weeks already, but at that time I didn't know that this is the same problem.