I had a similar problem, the problem is that you are creating the user as HTTPD (or any user name you assigned to your Web Http server user).
My solution to the problem was...
1) create a user that has all rights on the folder you want to share (where the folders will be located) preferebly DON'T USE a public folder, that's a dangerous backdoor!
2) Once created the user, open a FTP connection with PHP (see the FTP commands) like this:
$conn_id = ftp_connect($host);
$login_result = ftp_login($conn_id, $ftp_user_name,$ftp_user_pass);
ftp_chdir($conn_id,"/your/FTP/Path/To/TheFolders/");
ftp_mkdir($conn_id, "/your/FTP/Path/To/TheFolders/Folders");
ftp_site($conn_id, 'CHMOD 0777 /your/FTP/Path/To/TheFolders/Folders');
if(!is_dir("/your/FTP/Path/To/TheFolders/Folders")) {
ftp_rmdir($conn_id, "/your/FTP/Path/To/TheFolders/Folders");
echo "Error: cant locate the directory";
}
ftp_quit($conn_id);
After that you will had the directory created AS THE SITE user not as the HTTPD user. Then you can upload as many data you want
Check that the FTP path and the FULL path of the site are not the same! Ie:
/home/sites/site1/web/folders ( full )
/web/folders ( ftp )
I hope that help