Internet Explorer crashes when using OWA

It sounds like you are using Internet Explorer 7 or later with OWA 2003 and have the S/MIME Control installed. To get things working directly, you’ll have to uninstall the S/MIME Control from your machine. It is listed in the software list as; Microsoft Outlook Web Access S/MIME To be able to use S/MIME Control again, contact your mail administrator and ask him/her to apply update KB924334 to the Exchange 2003 server. After this you can install the S/MIME Control again from the OWA Options screen.