I saw quite a few posts on this in the forums but no answer.
Thought I would give it another stab and see if anyone has found the cure.
I'm trying to include a Google Map in the CMS HTML box by pasting the <iframe> code into the HTML box that pops up.
Essentially the code consists of <iframe .....></iframe> When I click insert the map show up. I can click the HTML button again and my code has not changed.
However, when I view the page SilverStripe stops processing the code. It changes <iframe ....></iframe> to <iframe .../> Which really screws things up. In my case, there is an Include template that is not even processed (actually it is but the browser doesn't show it since it doesn't see the iframe as being closed.
When I go back to the cms and click the HTML button, voila! my code look just like always has. TinyMCE is not changing the code, but SS must be changing it on the fly as it includes it.