Why does CDI injection fail to work in a some modules, but not in others?

In my Java EE project, there are several "Java EE" modules and a web module. One of the Java EE modules provides a class to CDI that is to be used by the other modules:

@ApplicationScoped
public class XFactory {

  @Produces @Actual
  public X create() {
     return new X();
  }
}

They are injected into

   @SessionScoped
   public class Target implements Serializable {
       X x;

      @Inject
      public void setX(@Actual X x){
        this.x = x;
      }
   }

However, this works only in one of the Java EE modules and in the web module. In all of the remaining Java EE modules, injection consistently fails, and I am clueless as to why: All I get is WELD-1408, unsatisfied dependency.

All of the modules have beans.xml in the proper places, they all work as long as I don't switch to injection. Most of the target beans are already in use as injected beans in a JSF. What's special about the Java EE module that works is that the bean is injected into a servlet in the web module, not the JSF.

The project runs with Java EE 6, EJB 3.1 in GlassFish 3.1. Dependencies are managed by Maven 3. X itself is Serializable, to satisfy the passivating scopes.

Did you come across this before? What could I have done wrong?

Update: Added dependency management remark above.

Update: Corrected the position of @Actual in Target.

Update: Updated the description with more details after a day of experiments.

This appears to be a problem in Glassfish 3.1, in one of its included libraries, or possibly in JDK 6.

I have just updated my system to Glassfish 3.1.1 and JDK 7, and problem does not occur any longer.