For Leopard OSX 10.5 Firewall, the firewall settings has moved to Security tab in System Preferences. You have a few options for your settings. Allow Specific applications is perhaps the wisest choice. Stealth Mode should not make any difference to the use of LW. You can press the
+ button to add an application to the list (may need to add your Admin account password first by clicking the lock icon to allow you to change settings.)
See sample settings below:
Despite the image example above, I personally set the firewall into Stealth mode!
Once opening LW you may well get a few popup windows originating from the OSX system firewall, choose appropriate settings to allow LW full access.
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