No Mapped drives -XpPro/Win2k3 Server

This is a lardge mixed mode network consisting of Win2k3 server & W98/W2k/XP clients. The Xp clients can log on to the domain but will not bring over the mapped drives as per the login scripts. All other clients are working ok. The login scripts are not running on these machines even for Administrators.
Can anyone help please?

Thanks Gavin