The owner had a Logitech USB and PS2 mouse that died. They went out and bought some USB moues and you guessed it, the new mouse does not work in the USB to PS2 adapter.
If you didn't get it, the usb keyboard and mice must support PS2 signals to use those adapters.
Bob
Hi there,
I have a Belkin PS2 KVM and a mouse/keyboard PS2 to USB adapters, but when I use the adapters, the mouse/keyboard do not work. Anybody has an idea on how to make this work (or at least experienced that)?
Thanks for your help.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic