Help - FW-1 and FTP in DMz

[Moti Levy <mlevy () lannet com>]

Hi All , 
I am runing out of idea's so You guys are my last hope.
I have an ftp server in the dmz (wuftp )
I wanted to add another one (iis 4 ftp ) .
I've added the machine to the objects , an made a rule which is identical to
the unix ftp ( i.e ftp , ftp-data open to all ).
from my lan i can connect and do everything fine.
from the web i can connect no problem ( pass login and password stage ) .but
when i do ls i get stuck .
here's what i've tried .
I've switched ip's with the wuftp stations and it also was o.k up to the
point of ls .
I ve checked the rules but can't find anything diffrent .
another starnge thing.
if i remove from the services tab of the firewll the "enable ftp port data
connection " and eneble passive ftp " the iis ftp works fine but my users
cannot ftp to any where outside . they connect but cannot ls download or
upload files .
Help ?
Moti 
mlevy () lannet com