This may be your problem:
This error message could appear when you try to modify or to view GPOs in Windows Server 2003, Windows XP Professional, or Windows 2000Microsoft acknowledged the problem:SYMPTOMSWhen you try to modify or to view Group Policy objects (GPOs) on a computer that is running Microsoft Windows Server 2003, Microsoft Windows XP Professional with Service Pack 1 (SP1), or Microsoft Windows 2000, you may receive an error message that is similar to the following:The following entry in the [strings] section is too long and has been truncated.Some text may be displayed after this error message, and this text varies in different scenarios. Additionally, if you click OK in the error message window, a similar error message may be repeated. Each error message that is repeated has different text that is displayed after the error message.
This problem occurs because older versions of the Group Policy editor cannot interpret some string types that include more than 255 characters. These string types are included in parts of .adm files that are meant to be excluded by the “IF VERSION” construct.Typically, the problem occurs when you try to view or modify a GPO that has been viewed by a different workstation, and that workstation contains .adm files that use the “IF VERSION >=5” construct. When an administrative workstation views a GPO, the workstation automatically updates that GPO with the latest version of the .adm files. If the workstation’s .adm files are newer than the files that are contained in the \Adm folder of the domain GPO, the template files are updated. If the template files contain the “IF VERSION >=5” construct, when an administrative workstation tries to modify or to view the GPO, and the workstation does not have this hotfix installed, the errors occur.NoteAdministrative template (.adm) files that use the “IF VERSION >=5” construct are included in Microsoft Windows XP Service Pack 2 (SP2). This construct prevents unexpected behavior in some Group Policy settings when the settings are modified by older versions of the Group Policy editor.
Update for Windows 2000 (KB842933) maybe the fix. Check this knowledge base and see. Let us know if this fixes the problem.