Windows 7: Screen saver does not initiate

I have it set the screen saver to begin after 1 minute idle, but no matter which screen saver I set it to, they do not initiate.What needs to be done? thanks

btw/ the preview command initiates the screen savers just fine. They won't turn on after idle though.

edit:
It appears I need some kind of win 7 wireless mouse driver. I unplugged the usb for the mouse and the screen saver kcked in. How do I know what to download? On the Mouse it says Microsoft Wireless Optical Mouse 2000.

In device manager go to your 'mice and other pointing devices', right click your mouse, click properties, power management and untick 'allow this device to wake computer'.