Logon Denied with IE7 upgrade

Your device does not comply to current client security policies. message is coming from the anitivirus scan F5 is running. I recently was connecting with Windows 7 and firefox and running MS Essentials for Anitivirus. My company applied the latest update of F5 that would allow new antivirus products to connect and now My Windows 7 doees not connect regardless of what anitivirus I'm running. So I am at a lost as well.