Internet Explorer 7 Crashes when using OWA

Q. After I've installed S/MIME control, my browser is crashing any time I'm trying to send an email using Internet Explorer.

A. This is a known bug with MS Exchange, and you can resolve it by downloading a hotfix:

Update for Exchange Server 2003 SP2 (KB 924334)

If you have a Front End/Back End setup you MUST install this hotfix on all Front-End servers BEFORE installing it on the Back-End servers. Otherwise you might have issues with OWA

After installing the hotfix on the server you must uninstall the S/MIME control from the computers using IE7, and reinstall the new one from the server. You can remove the S/MIME control using Add/Remove Programs from the Windows Control Panel. Once its been removed, you will see the installation options available again in OWA.