Problems Logging On to a Windows 2000-Ba

My users get this error massage after the first login, if a user logs off then on again you get this error message.
[Error message:
Microsoft Networking
The domain password you supplied is not correct, or access to your logon server has been denied.]

Also some directories on a shared folder on the server are inaccessible. The shared directory has full access rights not sure why either of these problems happen. I have no problem event ID’s in the event log.

Any help is greatly appreciated
Thanks
Chris Day