Turn comments On – Off

have you ticked all the admin options for comments?
there is –
a:
the general ‘settings’ – ‘discussion’;
b:
for each post/page, there is a ‘discussion’ field below the post/page editor;
if you don’t see it there, click the ‘screen options’ tab near the top right of the ‘edit post’/’edit page’ pages; tick the ‘discussion’ box, and then you should have the ‘discussion’ field where you shhold be able to enable the comments for this particular page/post.