I been having the same problem. Logic doesn't recognize the XSKey. it was working fine yesterday then today nothing. the keyupdater didn't work because the update button is greyed out. But it does recognize it in 10.3.9... For some strange reason none of my dongles are being recognized in 10.4.10.
When I look at my system profiler all my usb keys are present. it's that all the Host Applications for those keys are not seeing they are there.