Unable to delete list by backspace at the document start

[ms428]

Steps to reproduce:

1. Minimal document (HTML):
   

   <ul>
   	<li>
   		a</li>
   </ul>
   

2. Place the cursor before "a".
   
3. Press backspace.

Expected behaviour:

The list should be removed and the document should contain "a".

Actual behaviour:

Nothing happens - the list remains in the document.

Tested on:

Windows 7, 64-bit, FF 3.6.16, FF4, Chrome 10.0.648.204, Opera 11.01

Additional notes:

• works fine on IE 9.0.8112.16421
• the list can have arbitrary number of items to simulate the bug
• using toolbar icon for outdenting works fine

[Jakub Ś]

Doesn't work in Opera, Firefox and Webkit.

[Jakub Ś]

Problem can no longer be reproduced in CKEditor 4.5.6.