So he decided to fix it himself. He has created a small ImageSharpeningBugfix patch script that corrects control panel's code and eliminates the problem, so if you are annoyed with image sharpening problem you may fix the problem with this script too. As usual, you'll need the latest RivaTuner to install the script. After extracting archive in RivaTuner's folder simply start the script located in PatchScripts\NVIDIA\ImageSharpeningBugfix and it will correct the control panel's code. Currently the script supports 56.xx/w2k/xp driver family only, however I'll probably extend the range of supported drivers if the users will demand it.
So everything is in your hands, Alexey is
waiting for your feedback in
RivaTuner's
forum
;)