In AutoCAD Release 14, you can open a drawing file stored on a remote network drive and a warning message will display, stating that the drawing is in use or is read-only. Although neither of these conditions exists, the drawing cannot be edited. This problem occurs primarily with third party file servers that use the SMB redirector network interface. (Third party Unix connectivity software using SMB services include Samba, Syntax and Digital Pathworks.) This problem has also occurred with Windows NT/95/98 servers.
Autodesk has identified an operating system timing conflict that some third party file servers interpret as a file sharing violation. At this time, Microsoft does not have a definitive explanation for the cause of this problem. Autodesk has developed a patch for AutoCAD Release 14.01 to resolve this problem by changing which calls AutoCAD makes during save operations. The patch can be downloaded from the Autodesk Technical Assistance site at http://www.autodesk.com/autocad14.01-patches or, if you do not have Internet access, please contact your Autodesk dealer