Class 'Browser' not found - after upgrade to 1.5.1.3

Hi, I just upgraded from opencart 1.5.0 to 1.5.1.3 by following the upgrade instructions and then running the upgrade script. The admin panels seem to be ok but when I try to access the store I get the following error.

Fatal error: Class 'Browser' not found in /home/kamicom/public_html/shop/catalog/view/theme/shoppica/template/common/footer.tpl on line 1

Any help or pointers would be greatly appreciated
- thx