Black Screen before login screen

[Guest]

Hello,

I've got a problem with Kubuntu 10.4.1 on my laptop. After a kernel update and 2 reboots, Kubuntu suddendly didn't want to show the login screen.
After choosing Kubuntu (Dual Boot Windows7 / Kubuntu with GRUB), it starts well, the Kubuntu logo/starting screen appears and then... black screen ! I even cant access to any text terminal with ctrl+alt+F1.
Kubuntu worked very well for almost 5 months , it's the first major issue since the beginning...
Any ideas how to fix it ?

ASUS X52J , CPU : i3, GPU : Nvidia Geforce 310M.

[Guest]

Sorry to bring up an old post, but I'm getting exactly the same behavior with Kubuntu 13.04 on my MacBookPro7,1. Only with nvidia drivers—with the nouveau driver everything works fine, except for the graphics intensive applications I need to run. Any idea on how to solve that issue? Thanks! Martin