Yes I am using subdomains. I hard coded the path.
http://blog.mydomain.com is my blog site
http://www.mydomain.com/forum is the forum url
I hard coded
Code:
chdir('/your/absolute/path/tothe/vbulletin/directory');
My posts appear in the forum. The only issue is the integration. Users coming from the forum remain logged out . On clicking the login link in wordpress it takes back to the forum homepage. and I am getting log out error. " There was an error in log out. Please click here to log out " . Also i cannot access wordpress admin through /wp-admin it takes me to forum home page.
As i said earlier, i cannot start blogging till this issue is sorted out. If you want i can reinstall wordpress as no content is present. I have done it twice. deleted tables and reinstalled wp.
If you want to take a look at my site , let me know. I will pm you details.