Just refreshed from CVS and did a build on Windows with ECL_THREADS = 1 and got these errors. I commented them out of the ecl-threads.def and it was ok. ecl-threads.def : error LNK2001: unresolved external symbol ecl_base_string_case ecl-threads.def : error LNK2001: unresolved external symbol si_set_funcallable cheers dean