CKEditor ordered list messed up (re-ordered) when deleting an existing bullet

[Setu Poddar]

Steps to replicate:
copy below snippet in 'source' mode

<p>Heading:</p> 
 <ol> 
    <li> 
	<ul>
	<li>List 1 Item 1</li>
	<li>List 1 Item 2</li>
	</ul> 
	<div>&nbsp;Sub heading</div>
	<ul>
	<li>List 2 Item 1</li>
	<li>List 2 Item 2</li>
	</ul> 
    </li> 
</ol> 

Repeat the steps below with Firefox, Chrome and IE8:

1. 1st scenario: Select the complete "List 1 Item 1" bullet line and then delete it.
   It works fine with Firefox and Chrome browser, the order of the list get mess up(re-ordered) with IE8 browser.

2. 2nd scenario: Now place the cursor at the very beginning of the "List 1 Item 1" bullet line and then backspace delete
   All Firefox/Chrome/IE8 browsers has this issue where the order of the list get mess up(re-ordered).