Black screen in logout and when closing laptop lid

[Guest]

So yesterday I installed Kubuntu to my laptop and have almost set up everything I need but there is this problem of black screen. Whenever I try to logout of session, I end up into black screen without even mouse visible. When I close the lid of my laptop and open it, it shows a black screen with mouse cursor but not anything else.

Is this problem derived from graphic drivers...? WHat can I do to fix it?

Some specs:
Video card: Nvidia GeForce GT 325M and Intel integrated chip
32bit