Lenovo athlon laptop

[Sergio de Almeida Lenzi]

Hello,

I bought a lenovo laptop (cpu amd dual core, graphics is radeon 6250

Everything woks, except the graphics that only works with driver vga at
1024x768.

if I use the "ati"  driver, it works in 1366x800 (that is the panel
resolution,
it works ok, but ONLY ONCE, that is, the gdm program opens the 
login menu, I log in, works all the applications: libreoffice, nautilus,
firefox,
audio, video.... 
but when I log off, then gdm resets the display and all I can see it is
a black screen.
if I reset the screen several times (about 16 times , by killing gdm)
using an ssh session... 
the login screen appears OK...

Seems that the ati driver is mapping the fb wrong...

Thanks for any help,

Sergio