Blank post.php and wp-comments-post.php

I am getting very strange problem, After I post anything on my site http://www.celebsgossip.net, I landed to blank page.( new post,edit post or new comments) Whatever i do gives blank page, but to surprise new post got published and new comments as well, it very annoying that i have to press backspace every time.

I have tried all the possible way to solve problem,

like remove all the ping from settings,
disabled all-in-one plugin
reupload all the core wordpress files.

Still problem is exit, any idea ?