perl Net::FTP vs Ncftp passive mode

[justme]

hi

i am working with Perl 5.004 on Solaris 8 and i am using Net::FTP
module
to transfer a file to an FTP server.
This FTP server was running in PASV mode and in the script, i specify
something
like
.....
$ftp->pasv();
.....
$ftp->put(...,...)
...
$ftp->quit.

But when i run the script, the error shows "Cannot open data
connection". I even used Passive=>1 but also the same error message...

Then when i download and install ncftp and run it using passive mode,
it works.
So the question is, is Perl's implementation of passive mode different
than ncftp's?
thanks