Main menu stays dark

[lesept]

Hi
I tried to install Schaps Advanced Config, just to try it. But after reboot phase, my top left menu (called in French "démarrer") stays black, until I click on it (wherever) with the stylus.
I used the SAC to undo all the changes I had made, but the problems persists. It must be a registry key somewhere.
Can anyone help ?
Thanks...