Well the problem seems to be caused by an unsuccesfull compilation of cpp_regex_traits.o At line 236 of cpp_regex_traits.cpp for instance a std::messages<char>::catalog is casted to an int and vacpp does not like it. I'm not very familiar with localization and I could not find any indication in the standard that casting the catalog type to an int should be possible (John?,Robert?)
As a last resort we could define BOOST_NO_STD_MESSAGES but this will AFAICT no justice to the vacpp compiler that _does_ provide the std::messages.
OK, this has come up before: the standard *requires* that std::messages<>::catalog is an int, and that on failure std::messages<>::open returns a negative value. However IBM in their wisdom have made std::messages<>::catalog a pointer type, now I understand why they're done this, but it makes it impossible to write portable code that manipulates std::messages IMO. John.