database errors, can not de-activate

Hello, Just installed WP-ecommerce. At first I received a memory overlimit message and then it seemed installed. However, every page of the commerce module shows a database error message for every item. So, based on the recommendation I went to de-activate it and every time I hit the Plugins tab I get the “Download or Open” popup! I can’t seem to seem to even get to the plugins page to deactivate! Help.