As I already told, none of other Windows programs which live in system tray use this "sliding" animation for closing of the main window. And I've never heard that some users had any problems with it. If a program has an icon in the system tray, it is clear that closing of the main window doesn't mean closing an application. Right now I use 12 programs which live in system tray, but only one of them use this closing animation. It is really non-consistent.