Vista - Networking XP and Vista networked fine even before Vista went RTM

I don't know what happened. Something happened on 7/26/07 and my XP
and Vista machines no longer see each other. I can get them resynced
if I do a system restore back to 7/26/07 but that is the only thing
have done that enables me to network the two pcs.

If I do not do a system restore every time and just try to connect
from Vista directly to XP it asks for my network login and password
and I guess I thought it would be so easy to remember that I didn't
write it down. Maybe if I could just delete the file with the network
password that might be enough to enable me to resync them without
having to do anymore system restores?

I hope so because in the last three days I have had to do the restore
once a day. This could get old. If anyone has an idea what might be
happening I would love to know.

At first I thought maybe it was a faulty Vista update but I stopped
automatic updates and the problem still keeps repeating. Thanks for a
clue.

Jan