Received error message "True Vector Monitor Failure" from my firewall

I am using Etrust and got this message the other night, "true vector monitor failure" as my firewall shut down. I rebooted and it appeared again. I have no idea what a true vector monitor is. So, I shut down my system and it appeared to be fine the next day. However, I would like to know what it is, what caused it and how to avoid it in the furture. I did try to go to the Etrust site and can't get in . Thanks, Babe p.s. im using winxp and IE if it matters. B.