Vanilla Theme issue (Page Not Found error)

I followed these directions:
1. Copy the /themes/default folder and rename it to your theme name so it sits in the root theme folder like this: /themes/your_theme_name.
2. Open the "about.php" file and edit the information to reflect your theme's information.
3. Create a custom.css file in the "design" folder of your custom theme.
4. Go to your Dashboard > Themes, and apply your new theme.
5. Edit the custom.css file to your heart's content. The custom.css file is added after the base theme's css. Alternately, you can completely replace the base theme file (style.css) by copying it from the /applications/dashboard/design folder into your theme's design folder.

my website is http://www.mysite.com and have added a subdomain (iforum) to my root folder so now the structure of the url is http://iforum.mysite.com

when i try to access the vanilla forum : http://iforum.mysite.com this show up correctly the Embedfriendly theme(Blue theme design).

and when i click the dashbord on top toolbar it takes me to the URL : http://iforum.mysite.com/settings/gettingstarted a page with white background and few hyperlinks like themes,admnistration,etc

and when i click themes or any other links it takes me to Page not found error to the URL : http://iforum.mysite.com/iforum/dashboard/settings/themes

The tables are created on the databse without any errors.

DB : MySQL 5.0

Any helps ,appreciated.

Thanks.