Well this is a known bug http://jira.jboss.org/jira/browse/JBWS-1762 :-(
The problem is in your web.xml file which looks like:
... <servlet> <servlet-name>Hello</servlet-name> <servlet-class>org.jboss.wsf.stack.jbws.EndpointServlet</servlet-class> <init-param> <param-name>jboss.ws.endpoint</param-name> <param-value>org.jboss.test.ws.jaxrpc.jbws124.HelloJavaBean</param-value> </init-param> </servlet> ...
Change it in the following way and try to redeploy.
... <servlet> <servlet-name>Hello</servlet-name> <servlet-class>org.jboss.test.ws.jaxrpc.jbws124.HelloJavaBean</servlet-class> </servlet> ...
If you can use packaged version of wars and ears then use them otherwise you'll face this problem very frequently.
it seems that just deploying the class files does not hot deploy the web service. you have to copy over a new web.xml for the web service to get hot deployed.
is there any plans to change this since the web.xml is not required anymore?