When the group differs from the login user these files are not shown.
Files should at least be shown if a group has rw permissions and the user is in or the user has rw permissions.
I figured this out using mod-fcgi, all files with permission fcgiuser:www-data, php running as fcgiuser.
New files can be created, edited and deleted although the webroot folder has also permission fcgiuser:www-data.
I thried this using phpWebFTP 4.0 and 3.3b both having this issue
Best regards Fabio