I have never heard of anything like this happening
nor do I think OpenACS or AOLServer could really
cause something like this (in fact if you try and
drop a package with openacs you will see that most of
the time it fails).
I would look at the postgres server log around the
time that the dumps stopped containing the data
and see if you see anything unexpected (the log
is in $PGDATA unless you have moved it).
You should also do a psql -l and see if the databases
you expect are there.
You might also check and make sure that there are not two
instances of postgres running (say 7.2 and 7.3) and that
you are looking at the instance you really expect to be
looking at.
