There should 2 arrows next to 'Kudoz activity' when you look at your profile. It should be possible to click them to not show your kudoz activity to visitors.
Have you tried that, and did it not work?
Aleksandr Okunev wrote:
I check the boxes and click on 'save'
button, but when I open myy profile
in another browser, as a visitor, I can
see all my Kudoz activity, which I want
Please, fix it.