Assuming the change history is complete then there may be a bug in the 1.2.3 version as it doesn't beep when the caps lock key is pressed as did the 1.1.1 version (which I'm about to reinstall).

I can understand why some people would not want this or in fact may not like the beep noise that 1.1.1 had but thats what options are for.

UPDATE: OK I can't delete the post so I may as well make it useful, it appears that the app doesn't have this option I was using the Windows "ToggleKeys" accessibility option which somehow got turned off. I have now turned it back on

OK, Windows "ToggleKeys" is working unreliably on my Windows XP computer and not at all on Windows 7, Googling seems to show that this is not uncommon.

I would now like to request this function in the app, probably allowing a wav or mp3 of your choice to override any default and probably two tones, one for on and one for off.