Load on startup is ignored - JaxWS webservice is always initialized first

I want to execute a servlet on startup to initialize my environment (for db access, resource management and so on).
This servlet just implements javax.servlet.Servlet.
The other services (using JaxWS) should be instantiated after the Startup-servlet to provide access to the created resources.
But they are always instantiated before the Startup-servlet, even if I use the <load-on-startup> parameter in the web.xml.