Hi!
:idea: You could try this, before open/change the keyboard:
- Select some icon on workbench window;
- Hold Right Amiga and strike "I" key : you'll must get the information of the icon.
- Start any aplication who have their own full-window;
- Hold down Left Amiga + "N" : you'll get the Workbench main window back.
That is a simple test to discover what key is bad.
If one of them really go bad, use that Aminet hack who very much good people use in towerised Miggys: solding two wires in the reset line to a push-button somewhere. :-D