For those who have been affected by getting an update this week, there are fixes now available. A tool can be downloaded to run from a USB stick on the affected computer (or burned to a CD for those computers where the update damaged access to the USB ports). The tool is available from http://download.nai.com/products/mcafee-avert/tools/SDAT5958_EM.exe
As always, if you need more help with this or any other issue, please contact us.