Stop eating "onclick" argument

Hi,

I've a content whose the HTML source code containts a link with an "onclick" argument.
When I copy the page content (not the source) and past this in a CKEditor textarea (in WYSIWYG mode), the "onclick" argument of the link disappears from the source.

For example, if I copy this page content : http://difoolou.net/bla.html (Ctrl-A & Ctrl-C) and paste in CKEditor (Ctrl-V), the HTML source code result is :

<tr bgcolor="#f3eedb" valign="top">
   <td class="TexteDeBasePetit" width="100">11/10 23:38:59 :</td>
   <td class="TexteDeBasePetit" align="left"><font color="blue">Tu donnes <b>1 PO</b> à <a style="cursor: pointer; text-decoration: underline;"><b>Le corbeau de Creasy</b></a></font></td>
</tr>