I'm trying to build Python with 64 bit support on AIX, so far I've encountered 2 problems, dynload_aix.c is not 100% 64 bit compliant (it includes some cast from pointer to (int)); this was causing python to SEGV when building extensions, after changing from int to long, the error is now ILL (SIGILL), there is a pointer to NULL: The call stack from debugger is: 0x000000 initstruct (structmodule.c - line 1508) _PyImport_LoadDynamicModule ( importdl.c - line 53) load_module (import.c - line 1365) import_submodule (import.c - line 1895) load_next (import.c - line 1751) import_module_ex (import.c - line 1602) PyImport_ImportModuleEx (import.c - line 1643) builtin___import__ (bltinmodule.c - line 40) PyCFunction_Call (methodobject.c - line 80) eval_frame (ceval.c - line 2004) .... Any idea ? Any help is always welcome. Can anybody help me out ? Davide