Win 2000 Srvr. Can’t map network Drive

Hi.

There is a Windows 2000 Server, SP3, and all hotfixes
installed, and IIS 5.5. The problem is that I can’t map a
shared drive to it from any networked PC, though I can do
the oposite (map a share from it to any machine on the
network).

When I try to map a drive to it from a networked PC, I get
the following error: Logon Failure: the user has not been
granted the requested logon type at this computer.

but the user has access atributes to the share, it was
working fine yesterday ! ! !

Can anyone P L E A S E help ?

Thanks