Windows XP taking 4-5 minutes when shutting down or restarting

Hello I am new to this board. I have had an ongoing problem with Antivirus 2009. The issue began a few days ago where initially when I clicked on the desktop icon to start Norton it would either not open at all or it would take a minute and then the splash screen would show. I was advised to uninstall and then reinstall product. Now it seems that when I shut down Windows XP SP3 it takes at least 4-5 minutes to shutdown and turn off. The Norton tech support analyst went to the settings section of Norton and disabled the product tamper proof option under Misc settings. Now XP shuts down normally. I really don’t think that option was ever disabled before and it was OK. What could be the issue? I really don’t want the tamper setting to be off all the time. Any ideas would be greatly appreciated. Thanks…                  Ken