Microsoft Visual Source Safe Error

We use Microsoft Visual Source Safe 6.0 (VSS) in our development environment which allows certain users to access a particular project to work on files. Recently we encountered an error which we can’t resolve. Some users are getting error “ Invalid DOS path” and “Invalid Handle”. This error appears for each and every file which we “Check-In” but no errors on “Check-Out”
I’ve searched the web for the answer but all I’ve got is that it’s an LAN issue which is dropping the connection. Since the users on VSS do not have the problem I can’t accept that this is the reason. Please help me on this.
