Jonathan Wakely wrote: >So now the question is what have I done to prevent those instantiations >appearing in libstdc++.so ? > > Absolutely NO idea! I would suggest: 1- Looking into io-inst.o in the build dir (both versions, -fPIC in .libs too) 2- Double checking the content of io-inst.cc 3- Re-compile by-hand io-inst.o Paolo.