Printers disappear

I am using Avast 6.0 Pro on a Windows Vista computer, connected to a domain controller.
After installing the driver for the Brother HL-4150CDN, everything seemed to work fine. A few days later all of the printers installed on the system disappeared. I uninstalled Avast and the problem seems solved. Any suggestions what goes wrong? Thanks in advance.

Hi,

did you receive and messages from the AutoSandbox or any other shield of avast! in the time between the installation and the printers disappeared? Maybe also check each shields log.