Hi all I have a annoying problem with xml serialization to a file or std::cout. I want to serialize my own classes to a file via filestream and everytime I get a xml_archive_exception with the error message unrecognized XML syntax. What I want to serialize is a child class from a class hierachy. When I only serialize the part of the mother class (with BOOST_SERIALIZATION_BASE_OBJECT_NVP) it works, but when I also want to save the members of the child classes I get this exception. I have exported every class with BOOST_CLASS_EXPORT and at the base class I have a BOOST_IS_ABSTRACT(baseClass). Gcc brings no warnings or errors and when I use a text archive, all works fine. Has someone an idea what I do wrong or some suggestions? Thanks Andreas Here is my build environment: GCC: Using built-in specs. Target: i686-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-4.1.1-r3/work/gcc-4.1.1/configure --prefix=/usr --bindir=/usr/i686-pc-linux-gnu/gcc-bin/4.1.1 --includedir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include --datadir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1 --mandir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/man --infodir=/usr/share/gcc-data/i686-pc-linux-gnu/4.1.1/info --with-gxx-include-dir=/usr/lib/gcc/i686-pc-linux-gnu/4.1.1/include/g ++-v4 --host=i686-pc-linux-gnu --build=i686-pc-linux-gnu --disable-altivec --enable-nls --without-included-gettext --with-system-zlib --disable-checking --disable-werror --disable-libunwind-exceptions --disable-multilib --disable-libmudflap --disable-libssp --disable-libgcj --enable-languages=c,c++,fortran --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu Thread model: posix gcc version 4.1.1 (Gentoo 4.1.1-r3) Glibc: 2.5 BOOST: CVS Build RC_1_34_0 from 19.02.2007 BJAM: Boost.Jam Version 3.1.13. OS=LINUX. Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc. Copyright 2001 David Turner. Copyright 2001-2004 David Abrahams. Copyright 2002-2005 Rene Rivera. Copyright 2003-2005 Vladimir Prus.