Had the similar issue. This occurs when you schedule CCleaner to run every X minutes/hours. When it fires off the tray gets populated with the ICON and focus is lost from the active window to the tray. About three seconds later after it is done focus is returned back to the active window. Active window being what I was working on before it fired off (word/firefox)..
Vista 64 Bit - CCleaner V2.15.815
(Downloaded from the main website). Will try the latest version and see if something new was fixed on this issue. Not major but bothersome when you are active working..
Robert
