black screen under opensuse 11.4 KDE4

A tower PC has an MB series ASUS M2NPV-VM equipped with NVidia GeForce 6150 compatible chipset on board. This works perfectly since about 3 years under OpenSUSE 11.2 with KDE4. Due to 11.2 no longer being supported, I’m trying to switch over to OpenSUSE 11.4.
To have both systems clearly separeted, I installed a (new) second 2TB HD which has to receive the 11.4 software; besides this addition, no other HW is changed oir added.
OS11.4 was downloaded from the official OpenSUSE site en burned on a DVD.
After a standard KDE install, “nouveau” is used to control the video (instead of the propriety NVIDIA, because access to ftp://download.nvidia.com/opensuse/11.4/x86_64 was denied atinstall time).
Immediately after installation, a full online update was performed.
Firefox, Dolphin, Libreoffice… are displayed correctly and perform well.

Then a “one-click-install” of a NVidia driver from OS SDB was performed. Yast declared a correct installation.

On reboot, everything runs OK until after the completion of the login screen.
Instead of the classic desktop, a full black screen is displayed, with only widgets displayed in the bottom panel line.
Clicking on the Firefox widget p.e. does just flikken the screen but nothing is changed except that the task FF is displayed in the bottom panel as “active”

When the cursor is placed at the bottom right corner, a double arrow appears letting resize the window; at a certain (smaller) size, suddenly the window lights up and everything appears has it should in the window…
Practically every application can be “shown” by resizing the application window; for certain windows the necessary down scaling leaves a window size of merely 6cm * 3 cm!
Submenus generate a black rectangle, but if one knows by haert the position line of each option, then cliking on it enables that option…

Please, Suse guru’s help me solve this problem so I can benefit of an up-to-date system; by the way, the same problem appears in Opensuse 12.1RC1.

Thanks in advance

Try adding: nomodeset
to the default boot
File:Nomodeset-example.jpg - openSUSE