I am using Firefox (mozilla firefox) both on windows XP and Linux (FC2 )But in Linux it is behaving some how strange. In linux i am using firefox version 1.0
I am pasting here some lines from Java Script Console.
I got these errors when i was using hotmail or yahoo.
All these errors are indicating that those sites are not meeting some standards that Firefox is expecting; so it is merely indicating to you that there were some violations. Surely you will get these kinds of violations since places like Hotmail (MS) are not completely respectful to web standards like W3C. It depends on the site.
You can go to a particular webpage which has been written in such a way that only a IE browser could make sense of it. If you are still able to browse the sites than it's just what i've explained and you can't do much about it, besides disabling Java Script in the "Web Features" section of Firefox's control settings (but that won't help you).
If I were you I would at least upgrade Firefox on your GNU/Linux machine to 1.0.4. That will not necessarily fix those errors but there have been quite a few security fixes since 1.0. Additionally, I would stop using Hotmail/Yahoo - those services aren't GNU/Linux & standards friendly anyway, but that might not be something you would be willing to do - just food for thought.