Say if you have 3 ads on a page but also have an iframe embedded in the page with 2 more ads. Is this working against the TOS (maximum 3 ads of the same ilk) because in theory the iframe is a 'seperate' page.
A page embedded into a different page via an inline iframe is a different physical page?
That's your definition. I would probably define it differently. It's a different URL, but displaying on the same page. That's what an iFrame does - it allows you to display content reference by a URL on a page with a different URL.