Strange Problem when Redirect to other Servlet using dispatch. Please help!

Question

I've a servlet which will check login session first, if not logged in, it will redirect to LOGIN servlet using "req.getRequestDispatcher(forwardTo).forward(req, resp);", it works fine. For eg, if I press ServletA it will redirect to LoginServlet. It works fine IF I DON'T RESTART TOMCAT.
However, if I restart tomcat OR restart tomcat and close browser, then request ServletA again, it will display error:
Apache Tomcat/4.0.1 - HTTP Status 404 - /sun.userlogin
type Status report
message /sun.userlogin
description The requested resource (/sun.userlogin) is not available.
BUT if I press RELOAD, it will become normal and REDIRECT me to LoginServlet. It's very strange and it troubles my development. The following is a part of my code, do you have any idea what's going wrong?Thanks.
public class viewMyAcct extends HttpServlet
public void doGet(HttpServletRequest req,
HttpServletResponse resp)
throws ServletException, java.io.IOException
// Set the content type of the response
resp.setContentType("text/html");
// Create a PrintWriter to write the response
java.io.PrintWriter out = resp.getWriter();
HttpSession session = req.getSession(true);
if (session == null) {
out.println("ERROR: Internal servlet problem - no session");
out.flush();
out.close();
return;
UserLog ulog = (UserLog) session.getAttribute(USER);
cmd = new sqlcmd();
String uri = req.getRequestURI();
if (ulog == null) {         
String forwardTo = "sun.userlogin?where=RegForm"; //return to login page           
//String forwardTo = "../"+uri.substring(0,uri.indexOf(".")) + ".userlogin?where=RegForm"; //return to login page      
     req.getRequestDispatcher(forwardTo).forward(req, resp);
     //http://127.0.0.1:8080/user/servlet/student.userlogin
     //here sure have login,get user loginid
     else{
...

Answer 1

I got a reply why this problem occurs but do anyone of you know how to solve it? The reason is listed below:
Hi Ken,
The trouble starts when u restart tomcat,the servelet which is there in memory gets removed so the next time it has to cater to a request it has to go through init(), before getting into the service(), so when u restart and press for Re-login page,it has still not compiled, which it does on getting the first request and hence when u reload it, it responds