I use a quicksilver keyboard shortcut to activate screensaverengine, because I have to lock the screen every time I walk away from the computer and the hot corners simply don't work reliably. However, since I upgraded to leopard, the screen saver (only on the main screen) has become very glitchy, flickering between images no matter which built-in apple saver I use. (I do not have any third party savers installed.) when I move the mouse or press a key, the password box pops up over the screen saver, then a few seconds later, the screen saver disappears, but I have to click in the password box, it isn't automatically selected as it sometimes is/always used to be.