handeling PHP question

Have this strange problem with editing page that containes PHP code:
The php code is :
<a href="/newspage.php?p=<?php echo $id0; ?>" class="purple">Read more...</a>

and after editing somthing on the page(no matter what)it turns to be:
<a class="purple" href="/newspage.php?p=&lt;!--{123072647840931}--&gt;">Read more...</a>

I have enabled the following code in the fckconfig file but it didn't change:
FCKConfig.ProtectedSource.Add( /<\?[\s\S]*?\?>/g ) ; // PHP style server side code