Exception when webservice is invoked

I have a web service whose SEI is a stateless session EJB.
The EJB alone is deployed as a jar file in the JBOSS server.
The other supporting classes are made into another jar and then placed in the classpath
When deployed, there are no issues but when the web service is invoked, i get the
following exception

04:30:30,428 ERROR [SOAPFaultHelperJAXWS] SOAP request exception
javax.ejb.EJBException: java.lang.NullPointerException
        at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:63)
        at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83)
        at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
        at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:95)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
        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:110)
        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:408)
        at org.jboss.wsf.stack.jbws.RequestHandlerImpl.handleRequest(RequestHandlerImpl.java:272)
        at org.jboss.wsf.stack.jbws.RequestHandlerImpl.doPost(RequestHandlerImpl.java:189)
        at org.jboss.wsf.stack.jbws.RequestHandlerImpl.handleHttpRequest(RequestHandlerImpl.java:122)
        at org.jboss.wsf.stack.jbws.EndpointServlet.service(EndpointServlet.java:84)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
        at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179)
        at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
        at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262)
        at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
        at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:583)
        at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:446)
        at java.lang.Thread.run(Thread.java:595)
Caused by: java.lang.NullPointerException
--our supporting classes--
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:112)
        at org.jboss.ejb3.interceptor.InvocationContextImpl.proceed(InvocationContextImpl.java:166)
        at org.jboss.ejb3.interceptor.EJB3InterceptorsInterceptor.invoke(EJB3InterceptorsInterceptor.java:63)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
        at org.jboss.ejb3.entity.TransactionScopedEntityManagerInterceptor.invoke(TransactionScopedEntityManagerInterceptor.java:54)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
        at org.jboss.ejb3.AllowedOperationsInterceptor.invoke(AllowedOperationsInterceptor.java:47)
        at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
        at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:79)

Could some one please tell me if the way in which the web service is deployed is correct or not... that is splitting the jar file...

Friends,
Awaiting for your reply on this...
Can we split our web service jar file and deploy the bean alone in the application server placing the rest of the classes in the classpath?

I am using JBoss 4.2.2...

Thanks...