So I think you’re problem is the quotes in the href inside your function. Try escaping them like this and it should be fixed.
<p><?php _e("Sorry but, you are looking for something that isn't here. <br /><br />
Looking for more web developer jobs, please visit our sister site: <a href=\"http://LAMPjobsLA.com\">LAMPjobsLA.com</a>", 'cleanhome') ;?></p>