[boost] Problematic inclusion of "pthread.h".

When compiling the smart pointer tests with gcc 3.4.2 on Tru64, two tests fail with an error message. (See http://tinyurl.com/4jngu ) As far as I can see, the shared pointer implementation at some point includes the "pthread.h" system header file but gcc on Tru64 requires that -pthread must be specified on the command line when including this header file. When running this test with gcc 3.4.2 on Linux the file "pthread.h" is also included but gcc doesn't require the addition of -pthread in the command line on this platform. This leads to the question whether it is ok to include "pthread.h" without specifying -pthread on the command line. Does anyone know an answer to this? Markus