Thanks guys. Please find my answers to your questions : 1- Possibly he's using a 1.33.1 release on Windows and a CVS version on Linux -->I connect to a remote machine in which I do not have admin right. So, I used the default boost library. I did not download and install the newest version of boost. May be this is the cause. If you think so, how can I verify the version that are this machine. Any idea. 2- What is gcc -v saying? ----> Here is the display of that command: Reading specs from /usr/lib/gcc-lib/i386-redhat-linux/3.3.2/specs Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --disable-checking --with-system-zlib --enable-__cxa_atexit --host=i386-redhat-linux Thread model: posix gcc version 3.3.2 20031022 (Red Hat Linux 3.3.2-1) 3- That this error didn't become apparent und VC++ might have been caused by some compiler settings (precompiled headers, maybe?). ---> What do you mean ? Abdel.