Revisited "425 Can't open data connection"

Now on Windows 7 Home Premium I still get this error when somebody wants to connect to my server. However when testing on http://www.g6ftpserver.com/de/ftptest there is no problem when using EPSV. So my question is: does this give any clue how to make PASV work? How can I force an FTP client (FileZilla) to use ESPV?

Thanks and regards
Waffze