Missing MatWorks.Net MWArray API in Visual Studio 2010 and indows 7, C# Programming

Matlab R2009a Windows 7 x86 professional CHS Visual Studio 2010 Ultimate C#/.net 4.0

Problem: When I use "reference" to add mwarray api in visual studio 2010, it is not exist in the dialogbox, I know I can direct refer it from mwarray.dll, but when I synchronize the visual studio solution in other computer, the direct reference of mwarray.dll is not available. But in the visual studio 2008, I can use "reference" to add mwarray api.

Matlab R2009a windows 7 x64 professional CHS visual studio 2010 ultimate visual studio 2008 team suite

problem: In visual studio, the MathWorks,.Net MWArray API is missing. I can't refer it from "add reference" dialog box. It happens both in visual studio 2010 and visual studio 2008.