Fresh install amd64 11.1 does not starts graphical installer

After booting kernel and starting installation of amd64 11.1 yast says that I’ll have “less than 96Mb memory or X server could not be started”. System is HP DL160G35 with 6Gb installed and Graphics ATI Rage XL 8 MB onboard. All previous version (10.2/10.3/11.0) installs without problem in graphical installer.
At /var/log/Xorg.0.log I see following:

(II) VESA(0): Total Memory: 26 64KB banks (1664kB)
(II) VESA(0): Monitor[vesa]: Using hsync range of 31.00-48.00 kHz
(II) VESA(0): Monitor[vesa]: Using vrefresh range of 50.00-60.00 Hz
(WW) VESA(0): Unable to estimate virtual size
(II) VESA(0): Not using built-in mode “640x480” (no mode of this name)
(WW) VESA(0): No valid modes left. Trying less strict filter…
(II) VESA(0): Monitor[vesa]: Using hsync range of 31.00-48.00 kHz
(II) VESA(0): Monitor[vesa]: Using vrefresh range of 50.00-60.00 Hz
(WW) VESA(0): Unable to estimate virtual size
(II) VESA(0): Not using built-in mode “640x480” (hsync out of range)
(EE) VESA(0): No valid modes
(II) UnloadModule: “vesa”
(II) UnloadModule: “int10”
(II) Unloading /usr/lib64/xorg/modules//libint10.so
(II) UnloadModule: “vbe”
(II) Unloading /usr/lib64/xorg/modules//libvbe.so
(EE) Screen(s) found, but none have a usable configuration.

Whats wrong and how can I fix this?