MSBuild does not work with Net 3.5 MVC?!!

[shapper]

Hello,

I was trying to build an MVC application with MSBuild of Framework 3.5
and it does not work. Yes, I have SP1. The MVC application is Preview
5.

I always get errors as follows:

"App.Views.Shared.Error is not allowed here because it does not extend
class System.Web.UI.Page"

It seems like MVC ViewPage and others are not recongnized ...

Any idea of how to solve this?

Thanks,

Miguel