FTP Passive problem

Hello, I am having a problem where I cannot FTP in passive mode using an external IP to my FTP server behind the Fortigate 60B. When I FTP using the internal IP address the FTP works fine to the FTP server. The first item I noticed is when I use a FTP client the passive port range is not being used. I have used several different FTP clients such as WSFTP and Filezilla. If I eliminate the Fortigate the FTP works fine. The following is an example of the FTP external IP failure: PASV 227 Entering Passive Mode (208,xx,xx,66,132,187) connecting to 208.xx.xx.66:33979 - - connecting to 208.xx.xx.66:33979 ! Connection failed 208.xx.xx.66 - connection timed out ! connect: error 0 When it times out the FTP shifts into regular FTP and works fine. The fact that the login works and I get this far tells me the the FTP port is open. This following is an example when the FTP works using the internal IP address. PASV 227 Entering Passive Mode (208,xx,xx,66,92,28) connecting to 208.xx.xx.66:23580 - - connecting to 208.xx.xx.66:23580 Connected to 208.xx.xx.66 port 23580 This FTP works fine and it is using the FTP passive port range (23580-23590) that I assigned to the serv-u FTP server. My experineces with other routers is I have to open ports with port forwarding. I am not sure if this is the case with the Fortigate. Any guidence would be most welcome. Thank You, Joe