Hola comandosew!!!
Resulta que en mi portatil tengo la misma tarjeta gráfica que tu, y aunque físicamente no he instalado linux porque necesito hacer unas demos para mi proyecto fin de carrera con el SQL-SERVER de por medio (tiene los días contados

), si que he probado linux en el equipo con KNOPPIX 3.2. Y como en el fondo es una debian, pues te dejo mi configuración por si te puede ayudar.
lsmod:
Código:
Module Size Used by Not tainted
radeon 108164 0 (unused)
autofs4 8724 1 (autoclean)
af_packet 13448 0 (autoclean)
nls_iso8859-1 2876 0 (autoclean)
ntfs 50784 0 (autoclean)
trident 29076 0
ac97_codec 9992 0 [trident]
soundcore 3364 2 [trident]
pcigame 1384 0 [trident]
gameport 1276 0 [pcigame]
natsemi 17312 0
serial 51876 0 (autoclean)
usb-ohci 18120 0 (unused)
usbcore 57088 1 [usb-ohci]
ds 6472 1
yenta_socket 8640 1
pcmcia_core 37568 0 [ds yenta_socket]
rtc 6908 0 (autoclean)
cloop 5232 1
archivo /etc/X11/XF86Config-4:
Código:
Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "PS/2 Mouse" "CorePointer"
# Serial Mouse not detected
# USB Mouse not detected
EndSection
Section "ServerFlags"
Option "AllowMouseOpenFail" "true"
EndSection
Section "Files"
RgbPath "/usr/X11R6/lib/X11/rgb"
ModulePath "/usr/X11R6/lib/modules"
FontPath "/usr/X11R6/lib/X11/fonts/misc:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/misc"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi"
FontPath "/usr/X11R6/lib/X11/fonts/Speedo"
FontPath "/usr/X11R6/lib/X11/fonts/PEX"
# Additional fonts: Locale, Gimp, TTF...
FontPath "/usr/X11R6/lib/X11/fonts/cyrillic"
# FontPath "/usr/X11R6/lib/X11/fonts/latin2/75dpi"
# FontPath "/usr/X11R6/lib/X11/fonts/latin2/100dpi"
# True type and type1 fonts are also handled via xftlib, see /etc/X11/XftConfig!
FontPath "/usr/X11R6/lib/X11/fonts/Type1"
FontPath "/usr/share/fonts/ttf/western"
FontPath "/usr/share/fonts/ttf/decoratives"
FontPath "/usr/share/fonts/truetype/openoffice"
FontPath "/usr/share/fonts/truetype/ttf-bitstream-vera"
FontPath "/usr/X11R6/lib/X11/fonts/defoma/CID"
FontPath "/usr/X11R6/lib/X11/fonts/defoma/TrueType"
EndSection
Section "Module"
Load "ddc" # ddc probing of monitor
Load "GLcore"
Load "dbe"
Load "dri"
Load "extmod"
Load "glx"
Load "bitmap" # bitmap-fonts
Load "speedo"
Load "type1"
Load "freetype"
Load "record"
EndSection
Section "InputDevice"
Identifier "Keyboard0"
Driver "keyboard"
Option "CoreKeyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc104"
Option "XkbLayout" "es"
EndSection
Section "InputDevice"
Identifier "Serial Mouse"
Driver "mouse"
Option "Protocol" "Microsoft"
Option "Device" "/dev/ttyS0"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection
Section "InputDevice"
Identifier "PS/2 Mouse"
Driver "mouse"
Option "Protocol" "auto"
Option "ZAxisMapping" "4 5"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "true"
Option "Emulate3Timeout" "70"
Option "SendCoreEvents" "true"
EndSection
Section "InputDevice"
Identifier "USB Mouse"
Driver "mouse"
Option "Device" "/dev/input/mice"
Option "SendCoreEvents" "true"
Option "Protocol" "IMPS/2"
Option "ZAxisMapping" "4 5"
Option "Buttons" "5"
EndSection
# Auto-generated by KNOPPIX mkxf86config
Section "Monitor"
Identifier "Monitor0"
Option "DPMS" "true"
# HorizSync 28.0 - 78.0 # Warning: This may fry very old Monitors
HorizSync 28.0 - 96.0 # Warning: This may fry old Monitors
VertRefresh 50.0 - 76.0 # Very conservative. May flicker.
# These are some Modelines that happen to work on many systems
# Especially the "1024x768" has been thoroughly tested, even on Laptops
Modeline "640x480" 25.175 640 664 760 800 480 491 493 525 #60Hz
Modeline "800x600" 40.12 800 848 968 1056 600 601 605 628 #60Hz
Modeline "1024x768" 85 1024 1056 1152 1360 768 784 787 823
Modeline "1152x864" 92 1152 1208 1368 1474 864 865 875 895
Modeline "1152x864" 110 1152 1240 1324 1552 864 864 876 908
Modeline "1152x864" 135 1152 1464 1592 1776 864 864 876 908
Modeline "1152x864" 137.65 1152 1184 1312 1536 864 866 885 902 -HSync -VSync
Modeline "1280x1024" 80 1280 1296 1512 1568 1024 1025 1037 1165 Interlace
Modeline "1280x1024" 110 1280 1328 1512 1712 1024 1025 1028 1054
Modeline "1280x1024" 126.5 1280 1312 1472 1696 1024 1032 1040 1068 -HSync -VSync
Modeline "1280x1024" 135 1280 1312 1456 1712 1024 1027 1030 1064
Modeline "1280x1024" 135 1280 1312 1416 1664 1024 1027 1030 1064
Modeline "1280x1024" 157.5 1280 1344 1504 1728 1024 1025 1028 1072 +HSync +VSync
Modeline "1280x1024" 181.75 1280 1312 1440 1696 1024 1031 1046 1072 -HSync -VSync
Modeline "1600x1200" 162 1600 1664 1856 2160 1200 1201 1204 1250 +HSync +VSync
Modeline "1600x1200" 189 1600 1664 1856 2160 1200 1201 1204 1250 -HSync -VSync
Modeline "1600x1200" 202.5 1600 1664 1856 2160 1200 1201 1204 1250 +HSync +VSync
Modeline "1600x1200" 220 1600 1616 1808 2080 1200 1204 1207 1244 +HSync +VSync
ModeLine "1800x1440" 230 1800 1896 2088 2392 1440 1441 1444 1490 +HSync +VSync
ModeLine "1800x1440" 250 1800 1896 2088 2392 1440 1441 1444 1490 +HSync +VSync
EndSection
Section "Device"
### Available Driver options are:-
# sw_cursor is needed for some ati and radeon cards
Option "sw_cursor"
#Option "hw_cursor"
#Option "NoAccel"
#Option "ShowCache"
#Option "ShadowFB"
#Option "UseFBDev"
#Option "Rotate"
Identifier "Card0"
# The following line is auto-generated by KNOPPIX mkxf86config
Driver "radeon"
VendorName "All"
BoardName "All"
# BusID "PCI:1:0:0"
EndSection
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultColorDepth 16
SubSection "Display"
Depth 1
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 32
Modes "1024x768" "800x600" "640x480"
EndSubSection
EndSection
Section "DRI"
Mode 0666
EndSection
A simple vista lo unica diferencia un poco avismal que veo es que tu cargas el driver ati, mientras que a mi me carga el driver radeon en el XF86Config-4, puede que ese sea el problema

.
Espero te sirva,
saludetes,

kripton