I have a W2003 DC also running file and print sharing. Since a reboot a couple of days ago, legacy devices that used mapped printers to this server are no longer able to connect. These legacy devices all connect via IP - \192.0.0.2\printersharename.
On closer inspection, I notice that if browse to \192.0.0.2 I can see all shares but if I double click any of the printers I get "Operation could not be completed. Either the printer name was typed incorrectly, or the specified printer has lost connection to the network." However, if I browse to the netbios or FQDN of the same server, I am able to connect to the printers without any problem. It may also be relevent that I can access the shared folders using any method without error.
The behaviour described above is evident whether I try connecting from another LAN member or from the server in question itself.
Unfortunatley the legacy devices that connect via IP cannot be changed to use the netbios or FQDN.