Netscape’s Hidden Frame crashed

I have a PC running Windows98 with Internet Explorer 5.5 as the main browser, but also has Netscape 4.79 installed. (which is needed for a specific application, and was installed NOT as the primary browser) Both were working fine until the user installed AOL instant messanger. Although it has been uninstalled, everytime Netscape is opened there is a Norton Crash Gard message that says “Netscape’s Hidden Frame has Crashed”. Netscape has been uninstalled & reinstalled. Windows also has been reinstalled. Still with no effect on the problem. Any help would be GREATLY appreciated. Evidently there is some “Hidden file” that is not getting erased when the uninstalls happen and consequently the problem remains.