Manually editing database in code first entity framework

I have been trying out EF 4.1 (code first) with MVC 3. I am thinking ahead to when the application will need changes. I tested a couple of scenarios. I like the idea of manually editing the database when the model (my POCOs) would changed.

ASP.NET error when I change the model :

"The model backing the 'CTCMContext' context has changed since the database was created. Either manually delete/update the database..."

Now, it says that I can "manually update the database", but I did and still get the same error. Am I missing something !!?!

EDIT

Does this have to do with the model hash generate by EF ?