I haven't used my favorite VNC viewer in years. But today I installed the latest version (1.3.2a) and was unpleasantly surprised that I can't enter the Cyrillic letter "у". The capital letter "У" also cannot be entered - when pressing the corresponding key simply nothing happens. There are no problems with other letters of the Cyrillic alphabet.
I checked a few other viewers - there are no problems with Cyrillic letters. Only UltraVNC upset me.