FTP: Could not retrieve directory listing. Root dir "6.1/"

Hello.

WinSCP Version 4.0.0 (Build 342)
FTP
Norton commander
"Could not retrieve directory listing
/6.1/6.1/: no such file or directory."

FTP server on disk array has root dir "6.1/". CuteFTP deals with it normally. But WinSCP does a strange CWD:

Using FTP protocol.
Doing startup conversation with host.
PWD
257 "6.1/"
Getting current directory name.
Retrieving directory listing...
>> CWD /6.1/6.1/ << why?
550 /6.1/6.1/: no such file or directory.
Could not retrieve directory listing
(ECommand) Error listing directory '6.1'.
Could not retrieve directory listing
/6.1/6.1/: no such file or directory.

If "Remote directory" is set to "/":

PWD
257 "6.1/"
Changing directory to "/".
Synchronizing current directory "6.1/".
>> CWD 6.1/ << what for?
250 CWD command successful.
CWD /
250 CWD command successful.
Getting current directory name.
PWD
257 "6.1/"
Retrieving directory listing...
>> CWD /6.1/6.1/ << why?
550 /6.1/6.1/: no such file or directory.
Could not retrieve directory listing

WinSCP cannot deal with non UNIX-like paths yet with FTP protocol.