We are having a weird issue where various random clients are
disconnecting from the network when there not much activity (traffic) on
the network. It starts happening particularly after 6:00PM in the
evenings and also weekends. During the day, these same clients are fine.

Any ideas anyone? Clients using latest client version 4.91sp3 and server
running Netware 6.5 sp5. One of the weird things is that sometimes the
network drives for the Data volume disconnect and only certain
directories that you are working with are actually present but the rest
are gone. Then you have to reboot.