C# sample app Errors

Hi,
I am trying to run a Csharp sample "IE" from OpenCASCADE6.6.0 in VS2012 but I have errors like,
OCC, shell - These projects are out of date,
After building them I get:
Error 1 error C1083: Cannot open include file: 'Standard_Boolean.hxx': No such file or directory c:\opencascade6.6.0\ros\samples\csharp\occ\stdafx.h 16 1 OCC
Error 2 error C1083: Cannot open include file: 'Standard_Boolean.hxx': No such file or directory c:\opencascade6.6.0\ros\samples\csharp\occ\stdafx.h 16 1 shell
Error 3 Metadata file 'C:\OpenCASCADE6.6.0\ros\samples\CSharp\OCC\Debug\OCC.dll' could not be found C:\OpenCASCADE6.6.0\ros\samples\CSharp\IE\CSC IE
Error 4 Metadata file 'C:\OpenCASCADE6.6.0\ros\samples\CSharp\shell\Debug\shell.dll' could not be found C:\OpenCASCADE6.6.0\ros\samples\CSharp\IE\CSC IE

Warning 5 The referenced project 'shell' is targeting a higher framework version (4.0) than this project’s current target framework version (2.0). This may lead to build failures if types from assemblies outside this project’s target framework are used by any project in the dependency chain. IE

Warning 6 The referenced project 'OCC' is targeting a higher framework version (4.0) than this project’s current target framework version (2.0). This may lead to build failures if types from assemblies outside this project’s target framework are used by any project in the dependency chain. IE

Any ideas?
thank you in advance