diff --git a/src/i830_display.c b/src/i830_display.c
index 59ededc..d180b2b 100644
--- a/src/i830_display.c
+++ b/src/i830_display.c
@@ -1096,6 +1096,10 @@ i830_disable_vga_plane (xf86CrtcPtr crtc)
 
     vgacntrl |= VGA_DISP_DISABLE;
 
+    /* disable "VGA/Pop-up 2X Centered Mode Scaling" on 855GM platform */
+    if (IS_I855(pI830))
+        vgacntrl &= ~VGA_2X_MODE;
+    
     OUTREG(VGACNTRL, vgacntrl);
     i830WaitForVblank(pScrn);
 
