disappearing <br /> in non-empty listitem

[Koen Willems]

I'm having a problem entering <br /> in a non-empty listitem <li>
I would like to create XHTML as the following:

<ul>
<li class="decimal"><span class="ol">1. </span><em>Test 1</em><br />This line should appear on a new line, because a <br /> was entered with 'SHIFT + ENTER, just after '<em>Test 1</em>'.</li>
</ul>

But in fact in (Internet Explorer 7) when I hit SHIFT + ENTER a single time, the <br /> diasappears (for example: after switching to source-mode and back).
In Firefox i've no problem at all and SHIFT + ENTER behaves like expected!

I found two 'solutions':

1. Remove the <em> and </em> surrounding 'Test 1'
   
2. Hit SHIFT + ENTER twice!!!!
   
   

For me this is a huge problem, because the users of my CMS (most of them use Internet Explorer) of course would never think about hitting SHIFT + ENTER twice.

Regards,
Koen Willems