A good way to fix this without breaking any future functionality is to replace:
do_action( 'wpsc_user_profile_section_' . $current_tab );
In wpsc-user-log.php to:
if ($current_tab == 'purchase_history') {
include('wpsc-account-purchase-history.php');
} elseif ($current_tab == 'edit_profile') {
include('wpsc-account-edit-profile.php');
}else {
do_action( 'wpsc_user_profile_section_' . $current_tab );
}