Thanks @jggimi ! but it seems to be some other cause .. I got the segfault message after a first login right after a *fresh install* (a bit older macppc -current cd) .. now after an upgrade :
sysctl kern.version
Code:
kern.version=OpenBSD 5.2-current (GENERIC) #12: Tue Sep 11 14:32:34 MDT 2012
deraadt@macppc.openbsd.org:/usr/src/sys/arch/macppc/compile/GENERIC
and yet segfault still occurs when I login as when I launch a few applications ..
I've been using packages only .. could it be this old cpu failing to deal with packages compiled on new macppc hardware ?