WordPress posts does not show on post pages

I recently had a hack (Three times within three months)

That’s not good. Either you didn’t properly delouse your installation or you didn’t close the door the attacker came in via.

Thereafter i replaced index.php code in my WP installation

That’s not enough. When you are hacked 100% of your files are suspect.

However, the blog post was shopwn on the front page but not on the post page when i click on the post page.

Your home page http://windowsvj.com/wpblog/ shows that link http://windowsvj.com/wpblog/2013/02/get-current-url-using-php/ but when I click it I get a WSOD which means a 500 error on your site. In fact all of the links look to be generating a 500 error.

Check your server’s error log to see what’s crashing. Since you’ve been hacked in the past multiple times then you may want to give the standard reading material a good read.

You need to start working your way through these resources:
http://codex.wordpress.org/FAQ_My_site_was_hacked
http://wordpress.org/support/topic/268083#post-1065779
http://smackdown.blogsblogsblogs.com/2008/06/24/how-to-completely-clean-your-hacked-wordpress-installation/
http://ottopress.com/2009/hacked-wordpress-backdoors/

Additional Resources:
http://sitecheck.sucuri.net/scanner/
http://www.unmaskparasites.com/
http://blog.sucuri.net/2012/03/wordpress-understanding-its-true-vulnerability.html
http://codex.wordpress.org/Hardening_WordPress
http://www.studiopress.com/tips/wordpress-site-security.htm

What did your server logs say when those blank pages showed up? Us volunteers can’t help you unless you work with us and provide some more information.

Personally I think your still hacked but those logs would provide a clue.

I really can’t as that’s usually specific to your host. My own copies are in /var/log/apache but that probably doesn’t help you much.

Ask your host and please give those links I posted above a good read. They can help you get a handle on this problem.