problems with lock screen

[Rosanna Sordo]

> I'm encountering a big problem every time i lock the screen: I'm not able to 
> unlock it, i have to do a logout with ctrl+alt+canc.

Ok, the problems happens when i close the monitor of my laptop, like the 
standby of windows. I've removed this option from the control centre, but the 
problem is still here: the screen is half-sized, in the central part of the 
monitor. I can write commands, but they don't really suns.
 
Somebody knows how to disable the standby or whatever it is? 

Thanks

Rosanna