I did as suggested and there is no change. The posts order stays the same.
Is there any limitation in terms of number of posts? I have around 3500 posts in my blog.
Thanks. I tried firebug and clicking the update button is giving me 200 OK status but the order of the posts are not changed.
As I wrote above, when I refresh the Re-Order page at the admin panel, the posts are ordered at the same order previously.