The update of the file definitions is supposed to happen automatically.
Normallly there is not a problem.
The following things come to mind..
(1) Are you sure kirby alarm was not running when you updated your home computer?
(2) You could try copying the "file.upg" from your work computer to your home computer. This contains the details of the updated file definitions.
(3) If you don't have too many alarms set up you could just delete the alarm data files (ie delete *.tps)
(4) Send me your TPS files and I will update them for you and send them back.
Have a great day