Laptop with ati 200m card, screen blinks when unplugged

[Fukai]

Hi,
I have a HP laptop with a XPRESS 200M. I'm using the ati-drivers version
8.30.3-r1.
When my computer is unplugged, running on batteries the screen blinks
periodic (blink like turn off and on). This only happens when is unplugged
if it is plugged it don't happens.
I think this is a soft problem because this behavior start after some upgrade
of the ati-drivers. But now I update my xorg to 7.1 so i can roll back to some
older version of ati-drivers.

I already tried to emerge ati-drivers w/o acpi use flag but to no help.

Anyone have any idea of what is happening?

Thanks.

[teapot]

2 years ago I had issues with the screen on my centrino-laptop.
The backlight was turned off when I exited from X back to the console.

A reconfiguration of the kernel solved the problem. There are lots of experimental
graphics setting in the kernel , and many of them haven't been fully tested on TFT screens
to a very great extent.

I don't remember the exact change I made, but don't rule out that it is a kernel problem.

Good luck!