Engineer,
The simple solution is to plug the keyboard onto the PS2 Port. (You really do not need the extra bandwidth that USB provides. I have yet to meet anyone that can out type the bandwidth provided for the keyboard by the PS2 Port.)
Take Care,
Richard
P.S. I have seen where USB Keyboards are no longer recognized by the OS. Usually a fresh install of the OS was the only solution to get it working again via USB.