OS X 10.5 Macbook Pro (Intel Dual Core x86)

Boost builds and installs fine (except for Unicode Regex) and recognizes the toolset is Darwin.

   $./configure
   -n Building Boost.Jam with toolset darwin... 
   tools/jam/src/bin.macosxx86/bjam
   -n Detecting Python version... 
   2.5
   -n Detecting Python root... 
   /Library/Frameworks/Python.framework/Versions/2.5
   -n Unicode/ICU support for Boost.Regex?... 
   not found.
   Backing up existing Boost.Build configuration in user-config.jam.4
   Generating Boost.Build configuration in user-config.jam...
   Generating Makefile...

and make and install proceeded fine.

So I tried the examples on the "Getting Started Page"

First one works fine.
Second one (using the regex libraries does not):

"ld: warning in /usr/local/lib/libboost_regex-mt-d.a, file is not of required architecture
Undefined symbols:
  "boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >::maybe_assign(boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > const&)", referenced from:
      boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<cha"

So how can this be? The build was for Darwin and yet its the wrong architecture?!?!?!

I don't understand the error messages frankly.