I am sorted.

I don't see it in FF either.

This might help though:
A) Paste the code under "HTML View". In other words, don't paste it into the Tiny MCE editor view. IF this doesn't work, then:

B)
1) Go to the control panel of joomla and select "global configuration" or something to that effect
2) Disable the editor (it should be on tiny MCE or whatever. Change it to "none" or whatever it is
3) At this point, your text areas should be blank.
4) Paste in the raw html in the text area
5) Go back to #1 and #2 and select Tiny MCE again, if you wish.

C) If you want the ads to show in the header and footer section (globally), ignore A and B, and paste it directly in the HTML of the template, under template manager.

I was having problems integrating an iframe once, into a joomla site. Thanks to google, I found out I wasn't the only one with this problem. I ended up using option B above.

Good luck!