FTP component not filling directory list

I have been having intermittent problems when using the FTp control to list
all the files in the FTP server's directory.  I follow the steps in the
help.  I do the following  after I have connected to the ftp server:
  NMFTP1.ParseList := True;
  NMFTP1.Vendor := NMOS_AUTO;
  NMFTP1.List;
the resulting list has no entries.  I simultaneously log into the ftp server
and check for the existence of files in the directory and there is at least
one file.  I know that the server may be undergoing some changes and I
expect that this is causing my problem.  What can I do assure that my ftp
component configured and working properly.
Is there any property that I can set or check to make sure that the listing
of files is accurate.
TIA
DAN