I was faced with an issue in getting a second site up and running using virtual hosts, and this was down to a mistake in my httpd.conf file. If you encounter the following error in your log files:

[Thu May 27 12:44:54 2004] [warn] _default_ VirtualHost overlap on port 80, the first has precedence

You can resolve it by un commenting the following line in your httpd.conf line:

NameVirtualHost *

And then setting host directive to: , instead of specifying a server name. Courtesy of: Name-based Virtual Host Support.