Well, I THINK I have the same error.
I noticed two different error messages:
1. when use dante with lftp, I receive the same error message:
control-socket: Transport endpoint is not connected
I can't even connect to the remote ftp server through the socks proxy.
2. when use dante with ncftp, I can login to the remote ftp server, but when I try to do a "ls" to list the directory content, I receive the error:
Could not get socket name: No buffer space available.
List failed.
The funny thing is that when I use the default ftp client came with almost all linux distributions, it worked without any problem. But I do need those advanced features from ncftp or lftp.
I did some research, and from what I read, it might be a timing problem with dante (read this:
http://lists.debian.org/deity/2001/04/msg00004.html ), or maybe dante changed its API, but ncftp/lftp didn't catch up with it. And it seems that this is not a problem that can be fixed by simply adjusting some config values. A source code change might be necessary!