is a class.
is a package.
The bottom line is the jboss-seam.jar is not in your app server classpath. It may work for him due to his Eclipse (or other IDE) build path config.
If you're using JBoss 4.x, for example, try copying the jar to this location: \jboss-4.2.2.GA\server\default\lib to see what effect that has.
Also, build the Seam booking example. You'll see that the EJB jar is in the EAR root. so are the jboss-seam.jar and the WAR.
are you using Maven or Ant for builds?
I use ANT.
I am using the same Eclipse IDE myself to build and build path is exactly the same and still it seems the issue persists.
Also I am using JBoss 5.1