Hello,
I've had some difficulties compiling Smile .NET wrapper with Visual Studio 8.0. I wanted to get a wrapper with a debug DLL but I kept getting some weird linker errors. To fix this you have to remove /ZI option in SmileNET (Project Settings / C/C++ / Command Line). I guess it's related to porting the wrapper from .NET 1.1 to newer versions.
Hope it helps!