So I wrote some custom classes and put them all in a namespace, call it "Sphere".
On my aspx.cs codebehind file, I have "using Sphere;" written. I know that this works because it's always worked until I copied this project to a new folder. Also, even when I click "view in web browser" everything works perfectly.
Simply, Visual Studio 08 is not recognizing the namespace and so I cannot build without an error and consequently cannot debug. Thanks for the help!
edit: I have my namespace in my App_Code folder in a .cs file