Hi all,
finally I found a magical workaround to the problem. Since the point was
that the keyboard was not able to regain the control of SL once switched
back to the system, I changed the keyboard and used a SkinTek one, with the
upper row of keys managed by the "Office Lock" key. Once switched back to
SL, control successfully came back to the operating system by pressing the
"App Sw" key (or "Cut" key) on the upper row of keys. Probably one of these
keys sends a correct electric signal to my old CPU switch.
This was just to share with you my final experience.
Best regards,
Giovanni