Based on your description of the problem, my WAGŪ is the back-connection of active mode transfers is being blocked. This is a VERY common problem for endpoints behind a router/firewall.
This would probably be easy to verify if you could see the logs from the FTP server. Assuming you can't do that, and you know the IP address of the site you're connecting to, try looking at the D-Link's logs and see if there are incoming connections being blocked. If you see any, or just want to try a possible solution anyway, look around your FTP program's settings for "passive mode" and make sure it is enabled.