I originally posted this question at StackOverflow, but I'm beginning to think it's more of a server question.

I have installed ProFTPd on an EC2 instance running Ubuntu 10.10. I have managed my proftpd.conf file as well as my server permissions to be able to connect and upload/move files using FTP both remotely using Filezilla, and on the server itself when connecting to 127.0.0.1.

The problem I'm running into is when I try to upload/install a file using Joomla's interface.

I give Joomla the same login information that I give to Filezilla, and the connection is made in the same fashion. The ftp.log file actually shows that Joomla is able to login to the server:

localhost UNKNOWN nobody [17/Jan/2011:14:09:17 +0000] "USER ftpuser" 331 -
localhost UNKNOWN ftpuser [17/Jan/2011:14:09:17 +0000] "PASS (hidden)" 230 -
localhost UNKNOWN ftpuser [17/Jan/2011:14:09:17 +0000] "PASV" 227 -
localhost UNKNOWN ftpuser [17/Jan/2011:14:09:17 +0000] "TYPE I" 200 -
localhost UNKNOWN ftpuser [17/Jan/2011:14:09:17 +0000] "STOR /directory/store/location/file.zip" 550 -

But it fails when attempting the STOR command. I have traced the problem in the Joomla code to the PHP FTP module. The code (with my trace statements added):

if (@ftp_put($this->_conn, $remote, $local, $mode) === false) {
    echo "\n FTP PUT failed.";
    echo "\n Remote: $remote ; Local: $local ; Mode: $mode - Either ASCII: ".FTP_ASCII." or Binary: ".FTP_BINARY;
    echo "\n The user: ".exec("whoami");
    JError::raiseWarning('35', 'JFTP::store: Bad response' );
    return false;
}

Trace ouputs:

FTP PUT failed.
Remote: /directory/store/location/file.zip ; Local: /tmp/phpwuccp4 ; Mode: 2 - Either >ASCII: 1 or Binary: 2
The user: www-data

And in case you were curious, here is an example of the FTP log when using Filezilla:

my_client_ip UNKNOWN nobody [17/Jan/2011:16:45:55 +0000] "USER ftpuser" 331 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "PASS (hidden)" 230 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "OPTS UTF8 ON" - -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "PWD" 257 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "TYPE I" 200 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "PASV" 227 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:45:55 +0000] "MLSD" 226 3405
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:06 +0000] "CWD location" 250 3405
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:06 +0000] "PWD" 257 3405
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:06 +0000] "PASV" 227 3405
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:07 +0000] "MLSD" 226 3757
my_client_ip UNKNOWN nobody [17/Jan/2011:16:46:37 +0000] "USER ftpuser" 331 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "PASS (hidden)" 230 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "OPTS UTF8 ON" - -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "CWD /location" 250 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "PWD" 257 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "TYPE I" 200 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:37 +0000] "PASV" 227 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:39 +0000] "STOR file.zip" 226 125317
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:39 +0000] "PASV" 227 -
my_client_ip UNKNOWN ftpuser [17/Jan/2011:16:46:39 +0000] "MLSD" 226 497