It is most likely that the Xerces C++ library is compiled using a version of GCC which is different than the one you are using to compile your application. If that's the case, try recompiling both the library and you app with the same compiler. But without knowing how you are trying to link libdev_xml.a it's hard to tell. Mail the complete build log (including compiler command lines and linker output if any) to me privately (no need to post on this list) and I can try to help. Parag -- Sent from the gcc - Help forum at Nabble.com: http://www.nabble.com/Xerces-Error-t841718.html#a2195630