Finder sidebar: Shared Computers shows nothing

I have two computers in the house but neither computer shows anything in the Shared section in the Finder's sidebar. In fact, the Shared section header doesn't even appear.

Both computers are Leopard. Both have Finder preferences set to show everything shared. They're on the same network and they can ping each other. Both have Screen Sharing turned on and it works both ways using Go to Server or using the Screen Sharing utility . Both have the firewall set to Allow all incoming connections.

Do you have File Sharing turned on?

Even I've had this problem. Sometimes they show, sometimes they don't. Usually a restart does the trick. However, if you badly need to access your mac, then go to the Finder Menubar >Go>Network

Or you could do the usual Command+K and then enter the computer name in there (as shown in the Sharing preference pane)

Turns out restarting both computers did the trick. Also, in case anyone's interested, here's a nice thorough and easy to follow article on Leopard's screen sharing: http://www.macfixit.com/article.php?story=20071102122311545

It seems the problem lies with IPv6 - some shares don't use it but Leopard, by default, has it automatically configured. Just turn it off and flush the cache:
System Preferences > Network > Airport (or ethernet - whichever adapter you're using) > Advanced button > TCP/IP tab > Configure IPv6 drop-down > off.

Open terminal and type: dscacheutil -flushcache

Solution to shared computers missing from sidebar

http://ngpingching.ca/2008/06/18/or...omputers-in-mac-os-x-leopard-finders-sidebar/

Shared computers were showing up on in my Finder's sidebar until I reinstalled Leopard. However, if I booted from my external drive (I cloned my HDD before reinstalling Leopard), the shared computers would show up again.

Having found no solution on the net, I called Apple since I have AppleCare. That's where I got that solution.