I opened the site in Firefox, and Windows IE. Same results.

What is suppost to be on this page?

https://support.mozilla.org/en-US/kb/firefox-cant-load-websites-other-browsers-can

http://kb.mozillazine.org/Error_loading_websites

The aside tag with "ad" in it is hidden if you reduce the width of the Firefox window, so make sure that the window is wide enough.

@media all and (max-width: 1039px) {
	#main .ad160x600 {
		display: none;
	}

To FredMcDL: try to look at it on Chrome or Safari and you'll see the problem in Firefox (and apparently in IE as well)

To cor-el: the problem is with all the ads (look at the green ones as well), any way the media-query didn't help here, and I make the ad160 disappear in smaller windows, but in large screen it shows in Chrome and Safari and not in Firefox.

After using the developer tools it seems that Firefox ignore the HTML elements of the aside with ads altogether, like it is not a css problem at all (can it be that Firefox ignore the HTML element?). It is weird... And another thing: when I load a copy of the site on my local machine and browse with Firefox, I can see all the asides ads.

No problems here with the yellow and green ad's although the min-height (1400px) look unnecessarily high to me, so you need to scroll down to see the green container.

#main .box {
	min-height: 1400px;
	padding: 20px 7px;
	background: #FFF;
}

Hi mysched, are you sure you don't use any content filtering add-ons that could be removing the ad panels?

To cor-el , I'm not sure what you try to say, this is part of the code that I wrote and nothing changed? to jscher2000, No, none ad filtering (this is not even an ad yet, just a place holder to a future ad)

To test how Firefox runs "uncustomized" on your system, could you do a three-minute experiment?

Create a new Firefox profile

A new profile will have your system-installed plugins (e.g., Flash) and extensions (e.g., security suite toolbars), but no themes, other extensions, or other customizations. It also should have completely fresh settings databases and a fresh cache folder.

Exit Firefox and start up in the Profile Manager using Start > search box (or Run) by typing or pasting the following and pressing Enter:

firefox.exe -P

Do not delete anything here!

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like April12, ignore the option to move the folder and click Finish. Then start Firefox in the new profile you created.

Can you see all of the elements?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

What properties that affect displaying (e.g. display and visibility) do you see for those containers if you check this in the Inspector?

• https://developer.mozilla.org/Tools/Page_Inspector