ther is a little mistake in the code:
$total_user_images = $user_row['user_t_images'];
if u open memberlist.php page first time, it will show u 0 for users pics.
because $user_row['user_t_images'] contens information from not updated user_t_images column yet.
after u do page refresh it will show u the correct numbers.
so, to fix it, change that line to this:
$total_user_images = $count_t_images['t_images'];