"Bruno G. Albuquerque" <balbuquerque@dba.com.br> writes:
> Any pointers? Is there anything I can do for Windows to actually wait
> for the postgresql processes to clean up?
What it looks like to me is that your disk drive is lying about what
it's actually written; or possibly Windows is lying to Postgres about
what it's actually written. The former is pretty common and can usually
be fixed by turning off write caching.
regards, tom lane