Lose then regain NT Mappings

Database Application on an NT 4.0 workstation 4.0 accesses a database on the domain server. Application will crash because it can’t find the database tables.
A look in explorer indicates a lost connection to the mapped drive. A double click on the drive forces an authentication which of course reconnects via logon. I am unable to determine whether the application is the problem or whether it is a bug in NT.