Hi Alex,
I cannot reproduce the issue. I download that project CS-DataGridIntro_cs,
and I can compile and run it in my side without any problems. I can see an
similar issue in the following discussion,
http://silverlight.net/forums/t/14697.aspx
So what version of Silverlight Tools for Visual Studio you install in your
side? If you have installed the version 3 Beta, your development
environment will be a Silverlight 3 Beta environment. Visual Studio 2008
SP1 does not support multi-targeting for Silverlight applications so you
will be unable to develop Silverlight 2 applications once these tools are
installed. We recommend that you install the Silverlight 3 Beta tools on a
separate environment if you still need to have the ability to develop
Silverlight 2 applications.
Hope this helps! Have a nice day!
Best regards,
Ji Zhou
Microsoft Newsgroup Support Team