Check with Norton for an update. Or ask about that issue in the Norton support fora.

http://norton.lithium.com/norton/

I have version 1.3.4(15) of Norton Confidential. My computer is a Mac 10.6.7. When I tried to update following instructions on Norton, it tells me "This program cannot be run in DOS mode." I have no idea what this means. I still have "Error encountered" on the Firefox site. What do I do now?

Please try posting about that issue in the Norton Support fora. I have no Mac experience - too expensive for my needs, plus I build my own computers. As far as Norton goes, I have "sales associate" access to Norton security programs, and even being "free" I won't use their stuff - too much better stuff out there, that's less problematic.

After 2 hours on the Norton chat site and the "help" of four technicians, the problem persists. There final suggestion was to uninstall Firefox and the reinstall it. I am reluctant to do it. Anybody have better luck than me? I'm not sure whether the problem is with Firefox or Norton, but it is frustrating.