C# calling custom C++ DLL on Pocket PC - hx4700

Question

Hi Guys, I have been trying for hours (no, days!) to get a simple function that is exported in a C++ (eMbedded C++ 4.0) DLL that is loaded (on my brand new HP hx4700 Pocket PC) in the \Windows folder, to be called from a simple C# Smart Device compiled app (VS.NET 2003). The DLL code contains: // This is an example of an exported function. __declspec(dllexport) int fnSimpleDLL(void) { return 42; } And for those of you familiar with this, I have also tried a .def file that exports the fnSimpleDLL function without the embelishment. The C# code looks like: [DllImport("SimpleDLL", CharSet=CharSet.Unicode)] public static extern int fnSimpleDLL(); At runtime I get the fatal error System.MissingMethodException. I also have tried a similar exercise in VB.NET with the same result. Any ideas why I cannot get the C# to recognize the DLL or the function?