You haven't posted your whole code here, but I suspect the issue is with your .clear divs. If you have:
then this div:
Code:
<li><div><img src="Images/smallimg.jpg" /> </div>
<div><p><a href="#">4221 حالة إصابة مكتشفة بالإيدز فى مصر
</a></p></div>
<div class="clear"></div>
</li>
gets clear:both from the css at the top, but also inherits float:right from:
Code:
.anothernews li div {
float: right;
width: 48%;
}
So the clearing div is in itself floated and consequently doesn't clear the float. Making the clear div:
Code:
.clear{clear:both;float:none!important}
fixes the issue. If this doesn't fix it, then we need to see all your code, or preferably a link to your page.
(The validator allows a div within an li, but not one as a direct child of a ul)