Hi,

A couple of things to verify:

1.  If the NIS 2008 machine is trying to access the NIS 2009 machine, make sure the NIS 2009 machine has the network set to "Full Trust" or "Shared" (via the Network map).     If you more than 1 network adapter, you will need to set this policy on the adapter that's connected to the same network as the NIS 2008 machine.

2.  Are you accessing by machine name or by IP? 

3.  Are you accessing by a mapped drive?  If so,  what does the mapped drive map to?  IP address or machine name?

4.  A simple test to see if it's the Norton firewall is to disable it and try the connection (remember to re-enable afterwards).

5.  Finally, make sure they are on the same subnet.

Thanks,

/Chester