A few readers have asked me why their installation of Norton Internet Security 2009 won’t play nice with their copy of Firefox 3.5. Symantec now has an update to fix this compatibility issue. The problem was with the Norton Toolbar, a component of NIS2009 that Symantec markets as a way to encrypt and securely store your passwords and logins, and other sensitive data. I know many people who use this feature, so if you’re one of them, follow the instructions here to get this feature to work with Firefox 3.5. If you use NIS2009 but don’t store your personal data with the toolbar, there is no need to install this update. NIS has earned a bad rap over the years for being a slow, resource-hogging beast of an anti-virus program, but when I trialed the program for a few months, I found NIS2009 to be very fast and unobtrusive. Still,