/3GB switch not supported with WSS 3.0 or in WSS 2.0 after installing WSS 2.0 SP2
This important KB article has been released yesterday: 933560 The Windows Server 2003 /3GB switch is not supported in Windows SharePoint Services 2.0 or in later versions or in SharePoint Portal Server 2003 SP2 or in later versionshttps://support.microsoft.com/default.aspx?scid=kb;EN-US;933560