[Plugin: WP E-Commerce Dashboard] blank screen when adding adjustment to theme functions.php

Hi, I added this in order to display more than 5 products on my dashboard stats:

function my-adjustment-to-product-sales($current_limit) {
return 999;
}
add_filter(‘ses_wpscd_product_sales_limit’,’my-adjustment-to-product-sales’);

I use Atahualpa 3.4.6

any idea why this doesn’t work?

http://wordpress.org/extend/plugins/wp-e-commerce-dashboard-widgets/