Using Project Folders

Question

Hello.
I ran across a problem today with new forms/classes not showing up in IntelliSense, and the source not compiling when I try to instantiate recently added forms.
I added these forms within a folder under the project, and the new forms show up in the folder namespace in the Class View.
Yet these forms don't show up and I can't reference them in other classes.
I noted that their namespace is <application>.Forms (for example, I added a number of new forms into a "Forms" folder within the user interface application).
To regain the ability to use these new forms, I had to remove the .Forms section of their namespace from the designer.cs code.
Can anyone please tell me whether I'm doing something incorrectly? Should I organize a group of forms, for example, differently other than creating a project folder?
Thanks for any insight!
Tess