postgresql.conf listen_addresses causing connection problems

I recently have been attempting to get my install of postgresql 8.1
(running Win XP as OS) to listen on both 127.0.0.1 and my IP address,
192.168.0.100 (inside my network, obviously.) As such, I tried first
setting listen_addresses = '192.168.0.100, localhost'

With it like that, when I try to connect to the server using localhost
(I've tried this on a couple different clients) I get an error. If,
for example, I run psql -U user -d base, I get
"psql: server closed the connection unexpectedly
This probably means the server terminated abnormally
before or while processing the request."

Now, if I try again, this time with psql -h 192.168.0.100 -U user -d
base, it simply hangs, I don't even get a password prompt. Just for
fun, I let this sit for about 30 minutes, and it still did nothing. I
also checked the various logs I know of, and found nothing.

As a work around, I have tried setting
listen_addresses='192.168.0.100', however then I get an error about
half of the time, and it works normally half the time.

Setting listen_addresses='localhost' works just dandy, but then I
can't access the 'base except from home, and that's no good either.

Now, I did make some changes to my router recently, that I haven't
looked into yet, however, since this is all happening inside the
network, and mostly on the same machine as pgsql, I don't think that
would be it (correct me if I'm wrong.)

Any ideas? I'm fairly baffled, but then I'm a newbie.