On a Russian forum one user discovered that when connecting to some FTP server TC displays only "---" instead of Unix attributes. After switching to the LIST command the problem disappeared, so it has something to do with the MLSD format sent by the server. Here is the sample listing:
There's no UNIX.mode in the list, so no attributes. Output from FEAT command might be interesting, to see if perhaps server has that field disabled by default or does not advertise support for it at all.