A cursory glance at the module source reveals this gem:

...
         for my $line (@{$ra_lines})
             {
            @info = split(/\s+/, $line);
             $name = $info[$#info];
                        ...
[download]

So yes, filenames containing spaces are broken. A potential fix might be

            @info = split(/\s+/, $line, 9); # 9 columns in FTP output
[download]

... if one could be sure that each FTP server would return 9 columns of output. Another alternative could be to rely on the file date/time as a marker, or to try a fixed width parser for the ftp output, and checking that split /\s+/ always returns the same number of items.