Riddle me this, Batman: break and image tag swap

OK, so I'm running CKEditor 3.2 via the excellent rails-ckeditor plugin for RoR. Our web editor noticed that when she puts in an image, e.g.

<img style="width: 636px; height: 750px;" _cke_saved_src="http://site.com/style_0410_article1.jpg" src="http://site.com/i/style_0410_article1.jpg">

and then switches to Source View and precedes it with a break tag, like

<br />
<img style="width: 636px; height: 750px;" _cke_saved_src="http://site.com/style_0410_article1.jpg" src="http://site.com/i/style_0410_article1.jpg">

that when you click back out of Source View it is magically transformed to:

<img style="width: 636px; height: 750px;" _cke_saved_src="http://site.com/style_0410_article1.jpg" src="http://site.com/i/style_0410_article1.jpg"><br />

I'd love to be able to disable that nifty "feature" even it I have to turn off all HTML sanitizing. Is there a proper way to do this? By reading in the forums, I see other folks back in the FCKEditor 2.x days using the config FormatSource and FormatOutput to disable this "helpful" behavior, but I can't find any docs for 3.x.

Much obliged for any help...