DS SolidWorks Corp is now using Visual Studio 2008 SP1 to build SolidWorks 2011.
Microsoft Foundation Class (MFC) extension C++ addins or COM based C++ addins dynamically linked against MFC must be recompiled with the Visual Studio 2008 SP1 C++ compiler.
Please contact API Support at apisupport@solidworks.com with any questions.
SolidworksApi macros