I start an application client directly from inside Eclipse which performs a JNDI lookup (JBoss 7.1.0 GA server).
This fails with an exception because of missing JARs, see this forum post for the full error: https://community.jboss.org/thread/195162

Since I wrote this post, JBoss added a new library "jboss-as-7.1.0.Final\bin\client\jboss-client-7.1.0.Final.jar". After adding this JAR to the build path, my sample app worked. But for previous server versions (jboss-as-7.1.0.CR1), I had to add the JARs from my forum post.