Thanks for the quick response. I wasn't aware of the debugging error logging tool.
The debug error I get is as follows:
[17-Sep-2009 11:33:42] PHP Fatal error: Cannot redeclare class order in /home/lcstesti/public_html/development/store/includes/classes/order.php on line 1061.

My best guess is that it is a conflict between this module and a Gift Registry module I installed which also modified /includes/classes/order.php. I will research this further to see if I can resolve.