[Samba] Upgrading from Samba 2.2 to 3 causes WinXP machines to drop off the domain.

[Adam Luchjenbroers]

There is a single Linux server which acts as a PDC to a mixed network of
Win98\WinXP machines. We've recently upgraded from Samba 2.2 (don't have
exact version number available, the machines run RH7.2 if that helps).

After upgrading to Samba 3.0.6, the WinXP machines need to be re-added to
the domain. We maintain multiple sites with this configuration and are
hesitant to roll out this update to other sites until we've fixed this
issue.