WS_FTP - Cannot connect when using Zone Alarm and dial-up

Question/Problem: I cannot connect to any site when using WS_FTP Pro with Zone Alarm and a dial-up connection. Why?

Answer/Solution: This is actually a problem with Zone Alarm. 

A customer suggests: keep ZoneAlarm on High Security, and uncheck Block Internet Servers box. Another solution is to put ZoneAlarm on Medium or Low Security in which case it does not matter if Block Internet Servers box is checked or unchecked.

The following information was provided by Zone Alarm:

We are aware of the DHCP renewal issue and we are currently working on the fix. The short-term solution is to add the DHCP servers to your trusted
local zone. Some ISPs have required software to use in connecting to the
Internet. Some of these software packages have a command to display DHCP
server information. Please review your ISP connection software for this
command statement as it may vary from ISP to ISP. You will have to contact
your ISP for DHCP information since the DHCP servers vary from ISP to ISP.

Here is the screen for the current version of ZoneAlarm Pro:

To add a trusted IP Address to your Local Zone in earlier versions:

1.Click on the "Security" button to view the "Expanded Security panel".

2.Click on "Advanced".

3.Select "IP Address".

4.Under "Description", enter a name or description for the "IP Address".

5.Enter the name of the "IP Address". For example, "127.0.0.1" (no quotes).
This is the field where you will enter the IP address of the FTP Server you are attempting to access.

6.Click "Next".

7.Click "Finish".

8.Click "OK".

Some users have discovered this problem even when Zone Alarm is not configured to load on startup.