Well for starters, I use firefox. And so do a lot of other people, so your personal opinion about it doesn't change the fact that it's quite popular, and therefore worth considering
Secondly, if you had taken the time to read the thread from the beggining, you'd notice that Norton was just a hunch to what could be causing the problem, because the original thread starter never confirmed that he was using Norton. So what I did was to inform that the problem could also be caused by another thing other than Norton, Firefox.
And thirdly, as a tester, it's my duty to give as much possible information about any problem, and to try to help solve it