I am editing a page normally that has a "cms-editable" class. I switch to HTML entry and paste the following into the editor...
<iframe src="http://www.yourhost.com">
<p>Since you have an old, crappy browser, you have to
<a href="http://www.yourhost.com">click here</a>
</p>
</iframe>...I save it and it works great--so I thought! I forgot to set frameborder to 0, so I go back in and this is what my code looks like...
<iframe src="http://www.yourhost.com">
& amp;lt;p& amp;gt;Since you have an old, crappy browser, you have to
& amp;lt;a href="http://www.yourhost.com"
_mce_href="http://www.yourhost.com"& amp;amp;gt;click here& amp;lt;/a& amp;gt;
& amp;lt;/p& amp;gt;
</iframe>
Note how the inner content has been stripped of all the inner html and how it "attempted" to convert to HTML entities (which it didn't do it properly). And there is also that _mce_href that I have no clue why it is there. So everything is muffed-up and I wouldn't have known it because my browser doesn't suck.
It turns out you don't even have to save or publish it. You simply have to edit a cms-editable section, then go back in again.
Best Wishes,
Deen Foxx
P.S. The extra space between the & and amp; was necessary to get this message to show correctly.
