WD Netcenter - printer problem

Hello.
We have a WD netcenter with attached printer that has worked for a couple years, now can no longer print or even install the printer.

here is the setup:
Router: D-link dir-655 with latest firmware.
Netcenter: 250 meg, latest firmware. Printer attached by usb and shows connected and share applied. The shared drives are working just fine. Just the printing won't work.
Printer: Samsung ML-2010. Newest drivers installed on client pc's and mac.Printer operates fine when directly attached to pc via usb.

The only major change in our network was recent replacement of router; however going back to old router did not fix problem.

When trying to install to PC via usual add network printer, the printer shows up, there is long delay when installing, and once installed the status is permanently "opening", never ready. PC's all running Win XP sp 2.

When trying to install to Mac the netcenter shows up but not the printer, and when I try to connect to the netcenter I get "error: 256" and it asks for login and password, but none work. Mac runs OS x 10.4.9

Both PC's and Mac access the netcenter shared drives with no problem.

I tried unattaching and reattaching the printer several times, and tried a hard reset of the netcenter.

Any other suggestions? Did I leave anything out?