I use the following code to show/hide divs. It works just fine in Safari/Opera/Chrome. The page loads OK in Firefox (I get my show() effect), but if statement does not work in Firefox 3.6 for Mac. It seems that the jquery ":hidden" selector is busted? 

1. $(window).load(function(){
2. $(".page").hide();
3. $("#page1").show('slow');
5. //handle click
6. $("a.nav").click(function() {
7. var $source = $(event.target);
8. var $myPage = $source.attr("href");
10. if($($myPage).is(":hidden")){
11.                         //Firefox does not reach here
12.                         //alert("sad fox");
13. $(".page:visible").hide('slow');
14. $($myPage).show('drop',{direction:"right"},700);
15. }
16. return false;
17. });
18. });