I have a project that worked fine with .Net 2002 (7.0.9466). But when I open it up on .Net 2003 (7.1.3088) it compiles, but when it links I get the following warning: CDlgcEventProcessor.obj : error LNK2019: unresolved external symbol "public: __thiscall boost::thread::thread(class boost::function0<void,struct boost::empty_function_policy,struct boost::empty_function_mixin,class std::allocator<class boost::function_base> > const &)" (??0thread@boost@@QAE@ABV?$function0@XUempty_function_policy@boost@@Uemp ty_function_mixin@2@V?$allocator@Vfunction_base@boost@@@std@@@1@@Z) referenced in function "protected: int __thiscall DlgcFW2::CDlgcEventProcessor::StartThread(void)" (?StartThread@CDlgcEventProcessor@DlgcFW2@@IAEHXZ) Anyone have this kind of problem before?