Hi guys, I know this is probably a common problem, but I haven't found any help on any google searches so far... I've got my app compiling in debug mode fine using the boost_date_time and boost_filesystem libraries, compiling using Multithreaded Debug, but when I set up my Release mode compile using just plain Multithreaded I get a ton of LNK2005 messages similar to : error LNK2005: "public: static unsigned int const std::ctype<char>::table_size"(?table_size@$ctype@D@std@@2IB)already defined in libboost_date)time-vc71-mt-s-1_33_1.lib(greg_month.obj) I get about 70 of these errors between date_time and filesystem libraries. I'm linking against the same libraries (mt-s) both debug and release mode. I was hoping that someone could give me some advice. Thanks, Anthony