The gcc was upgraded from 3.2.3 to 3.4.3 when the Redhat linux was upgraded. On recompiling the applications, I got many errros similar to this one: Linking balance_refresher ... ../../lib/libinmateutil.a(DbUpdateBilledPartyWorkingBal.o)(.gnu.linkonce.t._ ZNSt14__simple_allocISsSt24__default_alloc_templateILb1ELi0EEE10deallocateEP Ssj+0x1a): In function `std::__simple_alloc<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__default_alloc_template<true, 0> >::deallocate(std::basic_string<char, std::char_traits<char>, std::allocator<char> >*, unsigned int)': : undefined reference to `std::__default_alloc_template<true, 0>::deallocate(void*, unsigned int)' When I did a search, I could not find stl_alloc.h anywhere in 3.4.3: pims-dev% pwd /usr/include pims-dev% find . -name 'stl_alloc.h' ./c++/3.2.3/bits/stl_alloc.h ./c++/3.3.4/bits/stl_alloc.h Is it replaced by something else or is it just missing by mistake? You help would be appreciated. Paul.