I connected to localhost (standard SFTP) on Port 8022.
It always told me that the connection was refused while other clients worked.
With logging enabled it turned out that WinSCP tried the IPv6 adddress [::1] and aborted after that.
My service was listening on 127.0.0.1 and WinSCP did not recognize it, when I didnt explicitly enter the IPv4 address.
I suppose this is a minor bug and would be delighted if you fixed this.
I also reckon that you know how a log-output of a failed disconnect looks like, so I won't provide any output :P
Affected OS is WIndows 7 here.