I had this problem last February but it never got resolved. Now when I try to enable protection for Firefox 3.5.6, SeaMonkey 2.01, or Flock, I get the Access Violation error message and the program closes. I believe all three are now using much of the same code. I use SpyBot and Avast Antivirus but no other 'protection' programs. My copy of Windows 2000 is 'current' with all updates. I did try uninstalling and reinstalling SWB 4.2 but that didn't change anything.