Just been trawling through the website and found tis in the cache folder:
[17-Aug-2012 21:25:46 UTC] PHP Deprecated: Function ereg() is deprecated in /home/corset/public_html/zen/includes/classes/db/mysql/query_factory.php on line 177

Any ideas?
Line 177 states:
if (!ereg('^[0-9]', $key)) {