I'm developing most of my web application using firefox, (it's much easier and there's no match for the FF-FireBug), before I check-in my changes I usually check the new pages on the other major browsers and most of the times there are only a few CSS isuues that easlly resolved, 

JS or jQuery for that matter never gave me problem on none of the other browsers EXCEPT IE!

In IE it turns out that the $.append() attribute won't replace contents , I though a could build a little work-around by using $.html() but ended up with the same result,

finally I figured it out, It seems that IE ignore the DOM injection if the HTML I'm tring to append is invalid (i.e. opening and closing tags match).  I guess it makes sence, but I still hate this browser!