Enter after horizontal line in Normail <DIV> adds two new lines

[tzweteto]

When horizontail line is inserted with Format Normal <DIV> the cursor is sometimes hardly visible and enter adds two new lines.
Steps to reproduce:

1. Open http://nightly.ckeditor.com/5635/_samples/skins.html[[BR]]
2. Select Format: Normal <DIV>[[BR]]
3. Insert horizontal line[[BR]]
4. Cursor is positioned bellow the line, which is correct[[BR]]
5. Click backspace - cursor is at the end of the horizonal line and hardly visible[[BR]]
6. Hit Enter -> two new lines are added and the format is changed from Normal<DIV> to Normal

[Jakub Ś]

After point 3, you will get the below:

<div>
	&nbsp;</div>
<div style="page-break-after: always;">
	<span style="display: none;">&nbsp;</span></div>
<p>
	&nbsp;</p>

Pressing backspace will move cursor to div above the horizontal line. To get next to this horizontal line you have to press down arrow two times quickly.
Now, pressing enter will result in two paragraphs.

Reproducible only in Firefox. Original TC was reproducible from CKE 3.0 to CKE 3.5.4 New TC has been reproducible from CKE 3.6 rev [6904]

Anyway, not very common scenario.