The problem with FTP listings is that there is no official standard for their format. Listing entries that use a format not supported by Rebex FTP are ignored, which is probably what happened.
Are you able to retrieve a list of files using the GetRawList() method instead of GetList()?
If you are, please mail us some sample output (or edit your question to include it) - that would make it possible for us to add support for this format to the next release of Rebex FTP.