Full Trust required in WPF web application

Hi All,

I don't understand how it could be:

1) I create an empty WPF web application;
2) open the project properties;
3) then open the Security tab;
4) select the "This is a partial trust application" option;
5) and click the "Calculate Permissions" button.

As a result I have the following message box:

---------------------------
Full Trust Required
---------------------------
This application requires full trust to run correctly. Would you like
to set this as a full trust application?
---------------------------
Yes No
---------------------------

Can somebody describe me why Full Trust is required for an empty WPF
web application?
Does the "Calculate Permissions" button work properly??

Thank you for any information in advance!!

(I have the WinFX Beta 2 Runtime Componets, Windows SDK and Orcas
installed on my computer)

Eugene.