Applet does not respond

Hi, I have an web application that will help in launch a few java appplets on a single click. However, when I open an applet and keep it inactive for a period of 30 min or more, the applet and the web application/browser hangs. The task manager shows that the applet and the application is running, but I'll be unable to do anything on them. I cannot even close them. This happened only after i upgraded to windows xp. It was working fine in windows 2000 pro. I tried reinstalling the windows xp, application that I work with, but no changes. Can someone help me? If you want something or some more info to analyze the problem.. i can send them to u. Thanks and Regards, kamal