Sorting the list of sites in /admin/content/toplist doesn't work

When you're editing the sites, if you want to sort the table by subject or contact, it doesn't work and makes an error in the watchdog, the solution is simple :
Find those lines:

array('data' => t('Subject'), 'field' => 'subject'),
array('data' => t('Contact'), 'field' => 'contact'),

and replace them with:

array('data' => t('Subject'), 'field' => 'site_name'),
array('data' => t('Contact'), 'field' => 'site_contact'),

now it works, easyl.