On Wed, 13 Nov 2002, Philip S Tellis wrote:
It appears that the port number for yahoo messenger has changed. While windows clients don't have a problem, the linux client has the port number written in its .ymessenger/preferences file
Change 5050 to 23 in there.
On further investigation, this could also be a firewall issue. If your firewall blocks port 5050, you can connect on port 23. Few firewalls block port 23 going out.