EJB Web Service - Failed to acquire the pool semaphore in JBoss EAP 4

Issue

• An ejb webservice that has been running fine for a couple of years, and recently a new web app started calling it and now I get this error:

  ERROR [org.jboss.ws.core.jaxws.SOAPFaultHelperJAXWS] SOAP request exception
  javax.ejb.EJBException: Failed to acquire the pool semaphore, strictTimeout=10000
       at org.jboss.ejb3.StrictMaxPool.get(StrictMaxPool.java:122)
       at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
       at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
       at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
       at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:108)
       at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
       at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46)
       at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
       at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
       at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
       at org.jboss.wsf.container.jboss42.InvocationHandlerEJB3.invoke(InvocationHandlerEJB3.java:103)
       at org.jboss.ws.core.server.ServiceEndpointInvoker.invoke(ServiceEndpointInvoker.java:220)
       at org.jboss.wsf.stack.jbws.RequestHandlerImpl.processRequest(RequestHandlerImpl.java:422)