IE7: List becomes distorted when Increase Indent is pressed

[James]

Steps to reproduce the defect:

1. Open the Ajax sample in IE7.
2. Paste the following code into the editor:

<ol>
	<li>
		line 1</li>
	<li>
		&nbsp;</li>
	<li>
		line 3</li>
</ol>

3. Select line 3 & click on Increase Indent in the toolbar.

Expected: A list 2 layers deep should display properly in the editor & you should be able to access all 3 lines in the list.

Actual: The list becomes obscured & there is no way to access the second numbered list item. (see attachment)

[Garry Yao]

Similar with #3165.

[Garry Yao]

Fixed with [6267].