Bad PublicKey, .NET Framework 4, VS2010 RC1 can’t build workable install (setup) program

I am developing a device application supported by Windows Mobile 6 SDK professional and using visual studio 2008 SP1

Does the .Net compact framework 3.5 SP1 support the namespace System.Data.Linq , since when I try click to Project-> AddReference and on .Net tap I can not find the namespace System.Data.Linq

Take a look at this threads.

Thank you very much I am aware that LINQ to DataSet is supported  but please can you see the below code        _Call_BlockDBDataSet _callBlock_db = new _Call_BlockDBDataSet();