Forwarding to JSP's through a servlet

I am developing an application which contains several JSP's and a servlet which acts as the controller. Between each page, control is passed to the servlet, some processing is carried out, and then the servlet forrwards to the next JSP. I have reached a point in the application when on returning to a page previously visited and clicking a link, I get a ServletException saying the servlet cannot be found. If I use the back arrow to go back, and then I try the link again, it works fine. Why might this be happening?

[533 byte] By [shirin2] at [2007-9-26 2:19:32]