Well - the system does not let you answer your own question so I had to make a new account.
I called Apple Support. WOW that was easy!! I can't believe how easy. Of course I was going to have to pay since the machine is so old (6 years), but since I had upgraded the OS to Leopard, it was FREE!
- First call:
They said run "Fix Permissions" from the Disk Utility app. Then in Sys Prefs>Sharing turn OFF all sharing - do a restart - then turn them back on.
This was a good idea but did not work.
- Second call:
So I went back online and got an immediate slot - no waiting!
SysPrefs>Security: Firewall tab:
There are 3 Options:
- Allow all incoming connections
- Allow only essential services
- Set access for specific services and applications.
The problem is that the list box is visible even when #2 is selected so it looks like the items are available. But they are not.
So I set to option #3 and was able to connect.
Not sure when my machine got changed, the other was probably changed at wife's work.
Hope this can help others.
BTW - Screen Sharing is awesome. Allows me to do a lot of compute intensive jobs on the faster machine while still on my main old G5.