HHKB PD-KB02 with green PS/2 to USB adapter

[HairyTroll]

I picked up one of the early HHKB's off of Ebay, PD-KB02.

The keyboard is in good condition and works well when connected to a PC via the PS/2 connector. However the keyboard does not work (in Linux or Windows) when using a green PS/2 to USB adapter.  Can anyone hazard guess why this does not work?

Is there a different adapter that I can try?

[EDIT]

Looks like I need a converter and not an adapter;

http://www.clickykeyboards.com/index.cfm/fa/items.main/parentcat/11298/subcatid/0/id/179740

[HairyTroll]

I can verify that the Belkin converter linked from the wiki does in fact work with this keyboard.