It seems that the "using namespace boost" statements in shared_ptr_132.hpp and shared_count_132.hpp trigger a problem in VC8 + SP1. Try the following small program: #include <boost/serialization/shared_ptr_132.hpp> #include <boost/cstdint.hpp> typedef unsigned short uint16_t; int main(int argc, char* argv[]) { uint16_t u; return 0; } Will result in this error: error C2872: 'uint16_t' : ambiguous symbol The workaround implemented for Borland works around the bug in VC8 too: #if !BOOST_WORKAROUND( BORLANDC, BOOST_TESTED_AT( 0x560) ) using namespace boost; #endif This problem was submitted to boost Trac (Ticket #1285). Unfortunately, the ticket was closed as "wontfix". Regards, Sean _________________________________________________________________ Put your friends on the big screen with Windows Vista® + Windows Live™. http://www.microsoft.com/windows/shop/specialoffers.mspx?ocid=TXT_TAGLM_CPC_...