"Comments are closed" After Upgrading to Wordpress 3.0

Hi,

I am encounter "Comments are closed" problem after upgrading my all my blog to Wordpress 3.0
This mean, my comments section are closed for every new post after 3.0 version.

Comments section in previous posts are still available.
I try to switch to default Kubrick theme and disable all plugings but it still the same.

Any idea how to rectify this error?

 

Try going to Settings/Discussion and see if the comments have been turned off.

Almost forgot that you can turn it on or off manually on each post or page you make, just scroll down a bit.

 

I have checked Setting > Discussion, it's turned on.

On each post itself I tick both checked boxes to turn on the comments and trackback.

However the comment section still do not appear.

 

Way out my league. You might be better off posting at the WP forums.

http://wordpress.org/support/

 

I have joined wordpress forum but still no respond.

If they respond I will update here.

Anybody else have idea what should I do? Should I downgrade my Wordpress?