fsync and network ports

Hi!

I seem to be having a rather interesting problem. I'm using RH6.2,
retrofitted with PGSQL 7.0.2. When I start postgres using pg_ctl, and add
the option -o "-o -F" in order to disable fsync, everything still works -
except that the database is inaccessible via network.

Is there a workaround? postmaster.opts says that the option to listen on
port 5432 is enabled, but when I telnet to port 5432, there is no service
running. If I take out the -o "-o -F", it all starts working again.

What is going wrong? Is this a bug? Or is network access disabled by
default when no fsync is used? How do I enable network access with fsync
disabled?

Thanks.

Gordan