Gutsy 32 > Probl. config affichage ecran loggin 800x600 au lieu de 1280x1024 at 75

[gire wanadoo]

bonjour sur Gutsy en 32bit
j'ai l'ecran de demarrage de session là ou on tape le loggin en 800x600 
au lieu de 1280x1024 at 75

comment faire pour le changer
merci



=====extrait du xorg.conf ===============================
Section "Device"
    Identifier    "Failsafe Device"
    Boardname    "vesa"
    Busid        "PCI:1:0:0"
    Driver        "nvidia"
    Screen    0
    Option        "AddARGBVisuals"    "True"
    Option        "AddARGBGLXVisuals"    "True"
    Option        "NoLogo"    "True"
EndSection

Section "Monitor"
    Identifier    "Failsafe Monitor"
    Vendorname    "Plug 'n' Play"
    Modelname    "Plug 'n' Play"
  modeline  "1280x1024 at 75" 25.2 640 656 752 800 480 490 492 525 -vsync 
-hsync
  modeline  "640x480 at 72" 31.5 640 664 704 832 480 489 491 520 -vsync -hsync
  modeline  "640x480 at 75" 31.5 640 656 720 840 480 481 484 500 -vsync -hsync
  modeline  "640x480 at 85" 36.0 640 696 752 832 480 481 484 509 -vsync -hsync
  modeline  "800x600 at 56" 36.0 800 824 896 1024 600 601 603 625 +hsync +vsync
  modeline  "800x600 at 72" 50.0 800 856 976 1040 600 637 643 666 +hsync +vsync
  modeline  "800x600 at 75" 49.5 800 816 896 1056 600 601 604 625 +hsync +vsync
  modeline  "800x600 at 85" 56.3 800 832 896 1048 600 601 604 631 +hsync +vsync
  modeline  "800x600 at 60" 40.0 800 840 968 1056 600 601 605 628 +hsync +vsync
  modeline  "832x624 at 75" 57.284 832 864 928 1152 624 625 628 667 -vsync 
-hsync
  modeline  "1024x768 at 85" 94.5 1024 1072 1168 1376 768 769 772 808 
+hsync +vsync
  modeline  "1024x768 at 75" 78.8 1024 1040 1136 1312 768 769 772 800 
+hsync +vsync
  modeline  "1024x768 at 70" 75.0 1024 1048 1184 1328 768 771 777 806 
-vsync -hsync
  modeline  "1024x768 at 60" 65.0 1024 1048 1184 1344 768 771 777 806 
-vsync -hsync
  modeline  "1152x864 at 75" 108.0 1152 1216 1344 1600 864 865 868 900 
+hsync +vsync
  modeline  "1280x1024 at 75" 135.0 1280 1296 1440 1688 1024 1025 1028 1066 
+hsync +vsync
  modeline  "1280x960 at 60" 102.1 1280 1360 1496 1712 960 961 964 994 
-hsync +vsync
  modeline  "1280x1024 at 60" 108.0 1280 1328 1440 1688 1024 1025 1028 1066 
+hsync +vsync
  modeline  "1280x960 at 75" 129.86 1280 1368 1504 1728 960 961 964 1002 
-hsync +vsync
  modeline  "1400x1050 at 60" 122.61 1400 1488 1640 1880 1050 1051 1054 
1087 -hsync +vsync
  modeline  "1400x1050 at 75" 155.85 1400 1496 1648 1896 1050 1051 1054 
1096 -hsync +vsync
  modeline  "1600x1200 at 65" 175.5 1600 1664 1856 2160 1200 1201 1204 1250 
+hsync +vsync
  modeline  "1600x1200 at 60" 162.0 1600 1664 1856 2160 1200 1201 1204 1250 
+hsync +vsync
    Gamma    1.0
EndSection

Section "Screen"
    Identifier    "Default Screen"
    Device        "Failsafe Device"
    Monitor        "Failsafe Monitor"
    Defaultdepth    24
    SubSection "Display"
        Depth    24
        Virtual    1280    1024
        Modes        "800x600 at 85"    "800x600 at 60"    "800x600 at 75"   
 "832x624 at 75"    "800x600 at 72"    "1024x768 at 85"    "800x600 at 56"   
 "1024x768 at 75"    "640x480 at 85"    "1024x768 at 70"    "640x480 at 75"   
 "1024x768 at 60"    "640x480 at 72"    "1152x864 at 75"    "640x480 at 60"   
 "1280x1024 at 75"    "1280x960 at 60"    "1280x1024 at 60"    "1280x960 at 75"   
 "1400x1050 at 60"    "1400x1050 at 75"    "1600x1200 at 65"    "1600x1200 at 60"
    EndSubSection
EndSection