JavaScript gets executed twice in FCK Editor

Question

I am facing a strange issue here:

I am using the FCK Editor. When I go to the 'Source' view and add some JavaScript to it, it executes fine. The JavaScript is supposed to display a random image. The issue is that putting the script in the FCK Editor executes the javascript twice, so the same image is also shown twice

On investigation I found that every time, this extra code gets generated which may be causing the error.

<script src="http://d1.openx.org/ajs.php?zoneid=654666&amp;amp;source=_self&amp;amp;target=_top&amp;amp;block=1&amp;amp;blockcampaign=1&amp;amp;cb=6665566882&amp;amp;charset=unicode&amp;amp;loc=http%3A//www.mysite.com/FCKeditor/editor/fckeditor.html%3FInstanceName%3Dctl00_MainContent_dvArticle_txtBody%26Toolbar%3DSite" type="text/javascript"></script>

Any ideas?