Oh, cool, thanks for find bug

In file <joomla>/administrator/components/com_jcomments/admin.jcomments.migration.php on string 746
$query = "SELECT c.*, u.user_email, u.name as user_name, u.username as user_username"
replace "u.user_email" with "u.email".
Bug will be fixed in the next version JComments.
Integration of JComments to HotOrNot2 galleryP.S> tested system - JComments 1.4.0.9, Joomla 1.0.xx, com_hotornot2_2.1_alpha3