Changing firewall setting in Apple program

Hello

In order to solve your problem, you need to install the latest MAC OS X.3.2 or later.

if you're not ready to update, simply follow this steps to resolve the issue.

first thing to do is to click on the finder icon in the dock, from the "Go" Menu, choose "Go to folder"

Type: /Library/Preferences/ and click "Go". Locate the file (com.apple.sharing.firewall.plist)

and drag it to the trash (Remember to see note first.) then from the "Apple Menu" , choose "Restart"

This removes any custom setting you applied to your firewall,

If ever you don't want to loose  your custom settings, heres another option. But remember, you must be comfortable with editing a text file in the terminal.

First, Open Terminal (/Applications/Utilities/).

Type sudo pico /Library/Preferences/com.apple.sharing.firewall.plist  and press "Return"

Input administration password when asked and press "Return".

now scroll down to this to lines

<key>allports</key> 
<array>

Add a new line directly under "<array>" containing this text 
 <string>515</string>

Then save the file (Ctrl-O) and return to confirm and exit pico (Ctrl-X) and restart your computer.