Phoneline networking

I just networked an XP machine and an ME machine with
Homefree's phoneline adapters (I have dialup internet
access), and the only problem I'm having is with the ME
machine-everytime I start or restart it, it tries to
automatically dial up the internet. I've made sure I have
the correct dialup settings, but the one area 'dial
whenever a network connection is not present' keeps
getting reset somehow to yes.

It is probably something really basic, but any help would
be appreciated.

Thanks!