After moving to Jaunty, I encounter a queer problem, which would display the following mesage, and Virtualhost would not work.
Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName
[warn] NameVirtualHost *:80 has no VirtualHosts
I had not changed anything, and copying same files from Hardy to Jaunty should have not caused an issue, since Apache's version remains the same, and so do the config files.
After scanning through apache2.conf, ports.conf, and all my website conf files, I could not find an issue. Then on a careful observation of the examples in Apache documentation I realized that a port definition was required in all virtual hosts.
So <VirtualHost *> would no longer work. One will have to change to <VirtualHost *:80> in all the websites. This fixed the issue.
New OS, new surprises!