Mac suddenly shown as UNKNOWN in "Attached Devices" on Wireless Router

[bernardlinde]

I have a small home network comprising my iMac G5 (10.4.7), and two XP laptops. One of the laptops is connected to a Netgear DG834PN Wireless Router via Ethernet Cable, and the other laptop and my iMac gets connection via wireless.

Yesterday I suddenly realised that my iMac is listed on the router's attached devices as UNKNOWN. Before, it showed my computers name (which I have NOT changed recently). MAC address is right though.

This does NOT affect my internet access - everything still going smoothly there. VNC also works, and even file sharing using my IP address. BUT my computer is no longer shown in the workgroup on the two Windows computers.

I have rebooted the router, upgraded the firmware, restarted my iMac, changed my iMac's name, repaired permissions, but still my computer is shown as UNKNOWN.

Anyone out there having a CLUE why this could be??