我们无法在.NET 4.0中的通用对象中使用Interop对象吗？

I'm working in VS 2010 and working on upgrading our application to .NET 4. The application is built with Excel as the base and we want to take advantage of some of the improvements to .NET for using Excel. But I ran across a strange error that seems to be caused by using an Excel Interop object in a generic dictionary. Here is the error that was generated:I'm working in VS 2010 and working on upgrading