i won't repeat my last message - it was long enough. Just wanted to stay, that i have understood that the Py_INCREF(self) in tp_new for the gobject types was wrong.
Setting tp_basicsize to (default + 4*sizeof(NULL)) is defensive, "1" instead of "4" - that is for the pointer to tp->dict - seems to be enough too.
Still all this leaves my fairly uncomfortable. Nobody there to risk an estimation ?
Thanks for reading, Joost