More investigation has revealed that this is also related to some compiler problem... tools/pwd_mkdb built with HOST_CFLAGS=-O somehow writes 00 00 00 00 7f 7f 00 00 for pw_change being 0. Changing HOST_CFLAGS to -O0, -O1, -O2, ... fixes this (00 00 00 00 00 00 00 00 is written). Masao