This is weird. You know when you lock your screen then the screensaver becomes active, then if you move your mouse a dialgue appears that gives the option to enter your password or to switch user.
Well, this dialogue disappears depending which screensaver I use. If I use flux, or euphoria, or similar 3d intensive screensavers, when I move my mouse after locking screen (either manually locking screen or timed screensaver activation), then this dialogue is not visible. I CAN type my password (after moving my mouse) to enter my present login, but switch user is impossible because I cannot get a cursor and the dialogue to be able to press the "Switch User" button.
Any ideas?? I am using an Acer notebook (brand new AMD V120 chip with M880G Radeon HD 4200 graphics card).