Yeah, sounds like passive mode issue. It's all about your and server's firewall rules. In active mode (which might be the default in certain ftp clients) data connections (directory listings, file transfers) are made from server to client.. it means client must have data ports open and not blocked by firewall etc. In most cases you don't have them open nowadays when you're behind routers etc.
With passive mode it's up to server to have everything needed open and client settings don't affect. It's usually made this way nowadays. So, check your client options and enable passive mode from it. All clients should have this switch in a way or another.
In DopusFTP it's found from ftp site's custom options, in miscellaneous page. DopusFTP should work just fine nowadays too, I'm using it regularly still (the original 5.82).
