Can you guys explain THIS?

I said earlier that I coded a shoutbox for a site.
Everybody sees it except the site owner.

The box was brought into the site with a <iframe>.

The owner doesn't see this <iframe> but the thing that happens when <iframe> is not supported by your browser. When I asked her to send me the source coude of her version of the page I discovered that her computer completely removes the entire <iframe> tag before IE can load it. (We didn't try Firefox yet, but considering the kind of the problem, I expect the same).

She has McAfee on her computer and I suggested to shut it down to see what happens. She claims it makes no difrence.

Now I wonder, what is it then?
What could cause a computer remove a <iframe> tag all by itself (and strangely <iframe> tags to other sites are left alone).

IE7 has a popup blocker which might be causing this. There are other security measures that block this kind of in site popups as well.

IE7, eh?
I knew I always had good reasons to hate Microsoft.
I'll try to look this up.

Yep, Firefox can block content by iframe. It is with an extension called AdBlock. I am sure M$ copied the functionality for IE. :)

try adding the website and the website the iframe is loading from as trusted sites in IE. this usually resolves security issues. iframing in a different website (i think that is what you are doing?) is considered a security risk.

Also check if he's got Google Toolbar installed and if so, disable its pop-up blocker as well.

By the way, pop-ups on websites REALLY suck. Don't implement them.