FTP over dialup connection fails

Hi,

Our development webMethods server is connected to our LAN through a normal network card, but also has a modem attached to it to dial out to the GEIS VAN. When we dial in to the GEIS network and connect to our GEIS mailbox through the command line FTP client, everything works fine. When we try to use the webMethods client FTP calls, we are also able to connect to our EDI mailbox, but we can’t do a get, put, ls, … All calls that try to open a FTP data connection fail, returning an error saying: “Can’t open data connection”. We opened the necessary ports on our server and we are also able to perform get, put, ls, … commands to other FTP servers that are not located in the GEIS network. I’m under the impression that this problem is caused by an IP address mix up between the network card address and the dial up connection network address. Has anyone experienced this problem before???