Problem in ERD creation in sql server management studio

I have downloaded adventurework database intall it then configure the databases in managemnt studio and then make a ERD of the db all works fine.

Then I have intall asp.net 2.0 starter kits.
1,Club Starter kit
2,Commerce Starter Kit
3,eBay Selling StarterKit
4,Jobs Site Starter Kit
5,Personal Site Starter kit
6,Time Tracker Starter kit

install them and configure the databases in managemnt studio.all thing works fine but when I create erd of any of these databases I get message

Database diagram support objects cannot be installed because this database does not have a valid owner. To continue, first use the Files page of the Database Properties dialog box or the ALTER AUTHORIZATION statement to set the database owner to a valid login, then add the database diagram support objects.

I have read the microsoft kbarticle but really no help.
If any body have gone through same situation and resolve it then please reply.

Thanks
Kamran Shahid
Software Engineer(MCSD.NET)
Progressive Systems (Pvt) Ltd.
Karachi,Pakistan
Tel :92-21-5675294-96
Cell :920304-2212616
Email :kamranshahid@.netprosys.com
:kamii47@.hotmail.comRight-click on the database in MS, select properties, and on the files tab, specify an owner for the db.|||When I check to database properties then file option it has the same owner that is (KAMI\Administrator) as of the databases (adventureworks,nortwind,pubs) whos ERD I am able to and have created.|||

That issue was also discussed here:

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=228352&SiteID=1

sql