We've upgraded our ELOG installation to v3, and we really like the new CKeditor. However, one of my users has noticed a problem when using Iframe HTML elements with CKeditor; namely that the HTML is not present when trying to edit the post, and saving the post erases the HTML. 
I was able to reproduce this fairly simply, by trying to embed a youtube video. I would create a new post, click the "Source" view in CKeditor, and paste something like the following:
<iframe width="420" height="315" src="//www.youtube.com/embed/RzZgFKoIfQI" frameborder="0" allowfullscreen></iframe>
Upon submission, this produces a totally normal .log file in the logbook directory, and the video is viewable on the ELOG page:

Date: Mon, 22 Dec 2014 15:52:20 -0800
Author: test
Type: General
Category: General
Subject: test
Attachment:
Encoding: HTML
========================================
<iframe width="420" height="315" src="//www.youtube.com/embed/RzZgFKoIfQI" frameborder="0" allowfullscreen></iframe>

Then, upon hitting "Edit," I am greeted by a totally empty CKeditor window, and hitting "Source" does not display the original HTML. 
Any help is greatly appreciated!

PS: Including the first line of the logfile in this very post would cause the submitted post to be truncated for some reason, although the preview looked fine. Pasting it here also caused the log to end abruptly. The string is "(dollar sign)(at symbol)MID(at symbol)(dollar sign): 9"